Prepare the mince: Divide the beef into four equal portions (about 125g each). Roll each portion into a loose ball — don't pack it too tight, or the texture will be dense. You want the meat to feel light and airy in your hands.

Get the pan screaming hot: Place a large frying pan or cast-iron skillet over high heat for at least 3 minutes. Add the vegetable oil and swirl to coat. The oil should shimmer and just begin to smoke — that's your cue that the surface is ready for the smash.

Smash and sear: Place a beef ball in the pan and immediately press it down hard with a spatula (use a second spatula to lean on it if needed) until it's about 1cm thick. Season generously with salt, pepper, and a pinch of garlic powder. You should hear a loud sizzle — that's the sound of a good crust forming. Cook for 3 minutes without moving it. The edges will turn dark brown and lacy.

Flip and cheese: Carefully flip the patty with your spatula. The cooked side should be deeply browned with crispy edges. Lay a slice of American cheese on top immediately. Cook for another 1½ minutes, until the cheese is melted and bubbly. The patty should feel firm but have a little give when pressed.

Toast the buns: While the patties rest, spread the softened butter on the cut sides of the potato buns. Place them butter-side down in a separate pan or on a griddle over medium heat for about 1 minute, until golden and fragrant. The smell of toasted butter and bread is the signal that they're ready.

Assemble the burgers: Spread a generous tablespoon of ShackSauce on the bottom half of each bun. Place the cheesy patty on top, then layer on the shredded lettuce, tomato slice, red onion, and a dill pickle. Add the top bun and press down gently. Let the burger rest for 30 seconds before serving — this allows the juices to settle back into the meat.