Start the Animal Style Onions: Melt 2 tablespoons of butter in a large frying pan over a medium heat. Add the finely diced onions and a generous pinch of salt. Cook, stirring occasionally, for 15-20 minutes. You're looking for them to turn a deep, golden brown and become soft and jammy. The sound will change from a loud sizzle to a gentle, buttery hiss, and the smell will become incredibly sweet and savoury.

Make the Secret Sauce: While the onions are caramelising, whisk together the mayonnaise, ketchup, mustard, pickle relish, white wine vinegar, smoked paprika, and garlic powder in a small bowl. Set aside. The colour should be a pale, peachy pink, and the aroma will be tangy and slightly smoky.

Prepare the Patties: Divide the beef mince into 8 equal portions. Roll each into a ball, then flatten into a thin patty, slightly larger than your buns (they will shrink during cooking). Season both sides very generously with salt and pepper. The patties should feel cool and firm to the touch.

Toast the Buns: In a clean, dry frying pan (or on a griddle) over a medium-high heat, split your buns and place them cut-side down. Toast for about 1-2 minutes until they are golden brown and smell wonderfully nutty. The visual cue is a deep, even tan on the cut surface.

Cook the Patties: Increase the heat under your large frying pan to high. Add the remaining 2 tablespoons of butter. Once it's foaming and sizzling loudly, carefully place 4 patties in the pan. Cook for 2 minutes without moving them. You'll see the edges turn a deep brown and the juices start to bubble on the surface. Flip them, immediately place a slice of cheese on two of the patties, and cook for another 1-2 minutes for a medium doneness. The cheese should be melting and soft.

Assemble the 'Animal Style' Base: On the bottom half of each toasted bun, spread a generous tablespoon of the secret sauce. Top with a slice of tomato and a handful of the caramelised onions. Place the cheese-topped patty on the onions.

Stack the Second Patty: Place a second, cheese-less patty directly on top of the first. Add another spoonful of the caramelised onions and a few pickle slices. The heat from the patties will warm the onions and pickles perfectly.

Finish and Serve: Place a piece of iceberg lettuce on top of the second patty. Spread another spoonful of sauce on the top bun half, then place it on the lettuce. Press down gently to meld the flavours. The burger should feel warm and heavy in your hands, the bun soft, and the patties firm. Serve immediately.