Prepare the potatoes for their first bath. Peel and cut your potatoes into 1cm-thick sticks. Rinse them in cold water until the water runs clear—this washes away excess starch. Pat them bone-dry with a clean tea towel. The sound of them rustling dry is a good sign. Heat your oil in a deep, heavy pan to 130°C. Fry the chips in batches for 5 minutes. They will look pale and soft, like cooked potato. That’s correct. Drain them on kitchen paper and let them cool completely. This first blanch is the secret to a fluffy interior.

Shape your patties with a light touch. In a mixing bowl, combine the mince with the salt, pepper, and Worcestershire sauce. Use your hands to mix gently—overworking the meat will make it dense. Divide the mixture into four equal balls, then press each into a patty slightly wider than your buns, as they will shrink. Make a small indent in the centre of each patty with your thumb. This stops them from puffing up into a dome. You want them to look like fat, juicy discs.

Get the onions caramelising. In a separate frying pan, add a knob of butter and a splash of oil over a medium-low heat. Tumble in the sliced onions. Stir them occasionally and listen for a gentle hiss, not a violent sizzle. Cook for 15 minutes until they are a deep golden brown and smell sweet and sticky. The colour should be like burnt honey.

Cook the patties to a perfect crust. Heat a large frying pan or griddle over a high heat. Add a drizzle of oil. Place the patties in the pan, leaving space between them. You should hear a loud, satisfying sizzle immediately—that’s the sound of flavour forming. Cook for 3-4 minutes on the first side without moving them. The edges will turn a deep, dark brown. Flip them, place a slice of cheese on top, and cook for another 2-3 minutes. The cheese should be just melting and drooping over the sides.

Toast the buns in the rendered fat. Once the patties are resting on a plate, add the halved buns to the hot pan, cut-side down. They will drink up the beefy juices and butter. Toast for about 30 seconds until they are golden and smell nutty. Watch them closely—they burn quickly.

Give the chips their final, glorious fry. Crank the oil temperature up to 190°C. Carefully lower the blanched chips into the hot oil. They should bubble furiously. Fry for 3-4 minutes until they are a rich, uniform golden brown. The sound will change from a wet splutter to a crisp crackle. Drain immediately and season with salt while they are still hot.

Assemble the masterpiece. Spread a little butter on the toasted bun bases. Layer on the lettuce, the cheesy patty, a pile of caramelised onions, sliced tomatoes, and pickles. Squeeze on ketchup and mustard. Crown with the bun top and press down gently. The bun should feel warm and soft in your hands. Serve immediately with the hot, salted fries.