To make this recipe properly, you will need a mincer attachment for your food processor. If you don’t have one, you can ask your butcher to help you out.
400 g (14 oz) grain-fed beef brisket, top layer of fat removed
400 g (14 oz) grain-fed beef chuck, excess fat removed
200 g (7 oz) dry-aged beef fat
The Caramelised Onions
50 g (13⁄4 oz) unsalted butter
3 large white onions, thinly slice
1 tablespoon brown miso
1 tablespoon vegetable oil
5 slices of American-style processed cheddar cheese
10 smoked bacon slices, about 10 cm (4 inches) in length
5 soft sesame seed hamburger buns, 13 cm (5 inches) in diameter
Japanese mayonnaise (Kenko brand)
3 large gherkins (pickles), sliced on a mandolin to 2 mm (1⁄16 inch) thick
Heinz Tomato Ketchup
For the patties, slice the brisket and beef chuck into nice long pieces that will fit inside the mincer. Transfer the slices to a bowl and put in the freezer for about 1 hour, or until the meat has just started to firm up. This will prevent the meat and fat from getting too hot and melting when going through the mincer. Carefully feed the meat through the mincer, making sure to alternate pieces of brisket, chuck and fat.
Put the mix in the fridge to firm up for 1 hour. Moisten your hands with a little vegetable oil, divide the mixture into about 5 x 140 g (5 oz) patties and flatten them out evenly between your hands. Make sure each patty is about 5 mm (1⁄4 inch) wider than the diameter of the bun because they shrink when cooked.
For the caramelised onions, melt the butter in a shallow saucepan over a medium heat, then add the onions and a pinch of salt. Cook over a medium heat, stirring continuously until the onions have softened and cooked down to a dark brown colour.
Add the miso paste and gently stir it through until well combined. Transfer to a container and keep warm.
Preheat a chargrill/grill plate to high for the bacon. Preheat the oven to 180°C (350°F/Gas 4). Meanwhile, to prepare the hamburger buns, place a bamboo steamer on top of a saucepan of simmering water over a medium-low heat.
To cook the patties, add a little oil to a large frying pan over a high heat. When the oil starts to smoke, season the patties on both sides with a little salt and place gently in the pan. Fry for about
2 minutes on one side and then flip. Cook the second side for 30 seconds. The patty should develop a nice brown crust.
Top each patty with two slices of cheese, cover the pan with a lid and leave for 1 minute on the heat, which will melt the cheese. While the patties are steaming, grill the bacon on both sides until nicely charred, but not crispy. Soften the hamburger buns in the bamboo steamer for about 30 seconds.
To assemble the burgers, put a tablespoon of Japanese mayonnaise on the bottom half of a bun, smoothing it out evenly with the back of a spoon so it covers the entire base. Spread with an even layer of caramelised onions, then add a cooked patty, cheese side up.
Arrange two slices of bacon side by side on top of the cheese, then place the gherkin slices on top in a single layer that covers all areas of the patty. Finally, top the patty with ketchup, starting from the middle and moving in a spiral direction working towards the outside. Finish by putting the bun top on top. That’s it.