There are some Saturdays that simply call for a project in the kitchen—something that fills the house with a sweet, savoury aroma and asks nothing more of you than a little patience and a sharp knife. This Copycat Subway Sweet Onion Chicken Teriyaki Sub is exactly that: a slow, rewarding build of caramelised onions, tender chicken, and a glossy sauce that turns an ordinary sub roll into a proper weekend indulgence.

Recipe Overview

• Prep Time: 20 minutes
• Cook Time: 30 minutes
• Total Time: 50 minutes
• Servings: 4 generous subs
• Difficulty: Easy to intermediate

Why You’ll Love This Copycat Subway Sweet Onion Chicken Teriyaki Sub

• Real, deep flavour from scratch: Simmering the sauce and caramelising the onions from raw creates a richness you simply cannot get from a bottled dressing. The kitchen smells like a cosy teriyaki house by the time the chicken hits the pan.
• Total control over sweetness and salt: Store-bought versions can be cloying or overly salty. Here, you adjust the honey and soy to your own taste—balanced, savoury, and never claggy.
• A proper sensory cooking experience: This recipe asks you to slow down. You’ll watch the onions turn from crisp white to translucent gold, then listen for the sizzle of chicken hitting a hot pan. It’s meditative, not rushed.
• Perfect for feeding a quiet gathering: Whether it’s a lazy Sunday lunch with the family or a midweek treat you’ve been anticipating, these subs feel special without requiring a complicated shopping list.
• Customisable to the last bite: You can pile on extra vegetables, swap the protein, or dial up the heat. The base recipe is a canvas, not a cage.

Copycat Subway Sweet Onion Chicken Teriyaki Sub

15 min prep  ·  30 min cook  ·  4 servings

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Ingredients You’ll Need

• 500 g boneless, skinless chicken breasts (about 2 large breasts)
• 3 large white onions, thinly sliced into half-rings
• 120 ml low-sodium soy sauce
• 80 ml honey
• 2 tablespoons rice vinegar
• 1 tablespoon toasted sesame oil
• 2 cloves garlic, finely minced
• 1 teaspoon grated fresh ginger
• 1 tablespoon cornflour mixed with 2 tablespoons cold water (slurry)
• 4 sub rolls (about 20 cm each), split open
• 120 g shredded iceberg lettuce
• 4 slices of mozzarella or provolone cheese (optional, for a melt)
• Salt and white pepper to taste
• Neutral oil for frying (such as vegetable or sunflower oil)

Tip: For the most authentic texture, slice the onions as uniformly as you can. Thicker pieces will remain crunchy, while thinner ones melt into the sauce more completely—I aim for a mix of both for that lovely varied bite.

How to Make Copycat Subway Sweet Onion Chicken Teriyaki Sub

1. Start the sweet onion base: Heat 2 tablespoons of neutral oil in a large frying pan over medium heat. Add the sliced onions and a generous pinch of salt. Cook, stirring occasionally, for about 15 minutes. You’ll see the onions turn from stark white to a soft, translucent gold, and the air will fill with a mellow, sweet fragrance. They should be limp and glossy, not crispy.
2. Build the teriyaki sauce: In a small bowl, whisk together the soy sauce, honey, rice vinegar, sesame oil, minced garlic, and grated ginger. Pour this mixture over the cooked onions. Turn the heat up to medium-high and let it bubble gently for 3–4 minutes. The sauce will darken and thicken slightly; you should smell the sharpness of the vinegar mellowing into the honey.
3. Thicken to a glaze: Reduce the heat to low. Give your cornflour slurry a quick stir, then drizzle it into the pan while stirring constantly. Within 30 seconds, you’ll see the sauce turn from a watery sheen to a glossy, coat-the-back-of-a-spoon consistency. Remove from heat and set aside.
4. Prepare the chicken: Place the chicken breasts between two sheets of baking parchment and gently pound them to an even thickness of about 2 cm. This ensures they cook evenly. Season both sides with a pinch of salt and white pepper. The flesh should feel firm but not hard after pounding.
5. Sear the chicken: Wipe out your pan (or use a fresh one) and heat 1 tablespoon of neutral oil over medium-high heat until it shimmers. Lay the chicken in the pan—listen for a robust sizzle. Cook for 4–5 minutes per side. The underside should be deep golden brown and crusty, and the chicken should release easily from the pan. If it sticks, it needs another minute.
6. Rest and slice: Transfer the chicken to a cutting board and let it rest for 5 minutes. This is crucial—the juices need time to settle back into the meat. When you slice it, the knife should glide through without resistance, and the interior should be white and moist. Slice into thin strips against the grain.
7. Combine chicken with sauce: Return the sliced chicken to the pan with the sweet onion teriyaki sauce. Toss everything together over low heat for 1–2 minutes until every piece is coated. The chicken will look lacquered, and the sauce will cling to the meat rather than pooling at the bottom.
8. Toast the sub rolls: Split your rolls and place them cut-side up under a hot grill (broiler) for 1–2 minutes, until the edges are golden and the interior is warm and slightly crisp. Be careful—they go from toasted to burnt in seconds.
9. Assemble the subs: Lay a handful of shredded lettuce on the bottom half of each roll. Pile on the chicken and onion mixture generously. If using cheese, lay a slice on top of the hot chicken so it melts slightly. Close the sub and press down gently. The roll should feel warm, the sauce should threaten to drip, and the lettuce should add a cool crunch.

Tips From My Kitchen

• Give the onions time to truly soften: This is not a step to rush. Low and slow for 15 minutes allows the natural sugars to caramelise without burning. If the pan looks dry, add a splash of water rather than extra oil—this keeps the onions tender without making them greasy.
• Pound the chicken to an even thickness: This is the single biggest difference between a dry sub and a juicy one. Uneven chicken means some parts overcook while others stay under. A few firm taps with a rolling pin or pan base sorts this in seconds.
• Let the sauce reduce before adding the slurry: The initial bubbling of the soy-honey mix concentrates the flavours. If you add the cornflour too early, the sauce will be thin and floury. Wait until it looks slightly syrupy, then add the slurry for a polished finish.
• Use low-sodium soy sauce: Regular soy sauce can make the final sub overwhelmingly salty once the sauce reduces. Low-sodium gives you room to season later without going overboard. My husband, who’s usually picky, asked for seconds—and he’s very sensitive to salt.
• Toast the rolls just before assembling: A cold, soft roll will collapse under the weight of the filling. Toasting firms up the bread and creates a barrier that stops the sauce from turning the sub soggy within minutes. Do it right before you serve, not ahead of time.
• Slice the chicken against the grain: Look at the lines running through the cooked breast—those are the muscle fibres. Cutting across them shortens the fibres, making each bite tender rather than chewy. It’s a small detail that makes a big difference.

Equipment You’ll Need

• Large frying pan or skillet (preferably non-stick or well-seasoned cast iron)
• Sharp knife and cutting board
• Mixing bowls (one small for the sauce, one tiny for the slurry)
• Wooden spoon or silicone spatula
• Baking parchment and a rolling pin (for pounding the chicken)
• Tongs for flipping the chicken

Common Mistakes to Avoid

• Overcrowding the pan: If you pile all the onions in at once, they steam rather than caramelise. Cook them in a single layer, or do it in two batches if your pan is small. You want them to sizzle, not swim in their own released water.
• Wrong temperature for the chicken: Medium-high heat is essential for a good sear. Too low, and the chicken will boil in its own juices, turning grey and tough. Too high, and the outside burns before the inside cooks through. Medium-high gives you that golden crust and a moist centre.
• Skipping the rest time: Cutting into hot chicken immediately releases all the juices onto the board, leaving you with dry meat. Resting for 5 minutes allows the fibres to relax and reabsorb the moisture. It’s the hardest step to wait for, but the most rewarding.

Delicious Variations to Try

• Spicy Version: Add 1 teaspoon of sriracha or a pinch of red pepper flakes to the sauce while it simmers. For extra heat, toss some sliced jalapeños onto the sub with the lettuce.
• Vegetarian/Vegan Option: Replace the chicken with thick slices of halloumi (grilled until golden) or with firm tofu that has been pressed, sliced, and pan-fried until crisp on both sides. Use a plant-based cheese or skip it entirely—the sweet onion sauce carries the flavour beautifully.
• Different Protein: Thinly sliced beef steak or turkey breast work wonderfully here. For beef, cook it quickly over high heat until just browned; for turkey, follow the same method as the chicken but watch the internal temperature closely to avoid drying out.

What to Serve With Copycat Subway Sweet Onion Chicken Teriyaki Sub

• Crispy Sweet Potato Fries Recipe — the natural sweetness of the fries echoes the caramelised onions, and the crunch contrasts perfectly with the soft sub roll.
• A simple side salad with cucumber, tomato, and a light sesame-ginger dressing.
• Pickled vegetables or kimchi for a bright, tangy counterpoint to the rich teriyaki sauce.

Still hungry for ideas? You might also love Chick Fil A Chicken Sandwich Copycat Recipe, Easy Copycat Chilis Chicken Enchilada Soup from our sister kitchens.

Frequently Asked Questions

Copycat Subway Sweet Onion Chicken Teriyaki Sub

A homemade version of the popular Subway sandwich featuring tender sliced chicken breast in a sweet and savory homemade teriyaki sauce with caramelized onions, served on a toasted sub roll with crisp lettuce and optional melted cheese.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 45 minutes mins

Servings: 4 servings

Course: Main Course

Cuisine: American

Calories: 350

Ingredients Method Notes

Ingredients

  

• 500 g boneless skinless chicken breasts (about 2 large breasts)
• 3 large white onions thinly sliced into half-rings
• 120 ml low-sodium soy sauce
• 80 ml honey
• 2 tablespoons rice vinegar
• 1 tablespoon toasted sesame oil
• 2 cloves garlic finely minced
• 1 teaspoon grated fresh ginger
• 1 tablespoon cornflour mixed with 2 tablespoons cold water slurry
• 4 sub rolls about 20 cm each, split open
• 120 g shredded iceberg lettuce
• 4 slices of mozzarella or provolone cheese optional, for a melt
• Salt and white pepper to taste
• Neutral oil for frying such as vegetable or sunflower oil

Method

 

1. Start the sweet onion base: Heat 2 tablespoons of neutral oil in a large frying pan over medium heat. Add the sliced onions and a generous pinch of salt. Cook, stirring occasionally, for about 15 minutes. You'll see the onions turn from stark white to a soft, translucent gold, and the air will fill with a mellow, sweet fragrance. They should be limp and glossy, not crispy.
2. Build the teriyaki sauce: In a small bowl, whisk together the soy sauce, honey, rice vinegar, sesame oil, minced garlic, and grated ginger. Pour this mixture over the cooked onions. Turn the heat up to medium-high and let it bubble gently for 3–4 minutes. The sauce will darken and thicken slightly; you should smell the sharpness of the vinegar mellowing into the honey.
3. Thicken to a glaze: Reduce the heat to low. Give your cornflour slurry a quick stir, then drizzle it into the pan while stirring constantly. Within 30 seconds, you'll see the sauce turn from a watery sheen to a glossy, coat-the-back-of-a-spoon consistency. Remove from heat and set aside.
4. Prepare the chicken: Place the chicken breasts between two sheets of baking parchment and gently pound them to an even thickness of about 2 cm. This ensures they cook evenly. Season both sides with a pinch of salt and white pepper. The flesh should feel firm but not hard after pounding.
5. Sear the chicken: Wipe out your pan (or use a fresh one) and heat 1 tablespoon of neutral oil over medium-high heat until it shimmers. Lay the chicken in the pan—listen for a robust sizzle. Cook for 4–5 minutes per side. The underside should be deep golden brown and crusty, and the chicken should release easily from the pan. If it sticks, it needs another minute.
6. Rest and slice: Transfer the chicken to a cutting board and let it rest for 5 minutes. This is crucial—the juices need time to settle back into the meat. When you slice it, the knife should glide through without resistance, and the interior should be white and moist. Slice into thin strips against the grain.
7. Combine chicken with sauce: Return the sliced chicken to the pan with the sweet onion teriyaki sauce. Toss everything together over low heat for 1–2 minutes until every piece is coated. The chicken will look lacquered, and the sauce will cling to the meat rather than pooling at the bottom.
8. Toast the sub rolls: Split your rolls and place them cut-side up under a hot grill (broiler) for 1–2 minutes, until the edges are golden and the interior is warm and slightly crisp. Be careful—they go from toasted to burnt in seconds.
9. Assemble the subs: Lay a handful of shredded lettuce on the bottom half of each roll. Pile on the chicken and onion mixture generously. If using cheese, lay a slice on top of the hot chicken so it melts slightly. Close the sub and press down gently. The roll should feel warm, the sauce should threaten to drip, and the lettuce should add a cool crunch.

Notes

For best results, let the chicken rest before slicing and do not skip toasting the rolls. The cornflour slurry should be stirred just before adding to prevent clumping.

I’d love to hear how you get on with this one. If you try it, perhaps serve it alongside a batch of Crispy Sweet Potato Fries Recipe or a Crispy Chicken Sandwich Recipe for another satisfying meal. Drop a comment below and let me know if your kitchen smelled as wonderful as mine did—and whether anyone asked for seconds before you’d even sat down.