1 tbspvegetable oil10 slicessmoked speck (about 10cm long)5soft sesame seed hamburger buns (about 12cm in diameter), split2 tbspJapanese mayonnaise (Kenko brand)3large dill pickles, sliced on a mandolin into 2mm-thick slices5 slicesAmerican-style cheddarTo serve:Heinz tomato ketchupMeat patties400 gmgrain-fed beef brisket, top layer of fat removed400 gmgrain-fed beef chuck, trimmed of excess fat200 gmdry aged beef fat (see note)Caramelised onions50 gmunsalted butter3large onions, thinly sliced1 tbspbrown miso
For meat patties, chop meat and fat into long pieces that will fit inside your mincer and place in a bowl in the freezer until starting to firm up (1 hour). This prevents the meat and fat overheating and melting when going through the mincer.
Feed the meat through the mincer, alternating pieces of brisket, chuck and fat. Once minced, place return mix to the fridge to firm up for 1 hour, then divide into five 200gm portions. Flatten each evenly with your hands; moisten your hands with a little oil for this. Ensure each patty is about 1cm wider all round than your buns because they will shrink when cooked. Refrigerate patties until required.
For caramelised onions, melt butter in a shallow saucepan over medium-low heat, add onions and a pinch of salt, and cook gently, stirring, until dark brown, softened, and caramelised (40-50 minutes); scrape the caramelised bits from the bottom of the pan during cooking, especially near the end. Once onions are totally cooked down, mix in miso paste, transfer to a container and keep warm. Makes 200gm.
Preheat oven to 180C. Heat a char-grill pan over high heat and heat a bamboo steamer if you are going to steam the buns. Heat a large ovenproof frying pan over medium-high heat, add vegetable oil and when it starts to smoke, season patties with salt and fry for 2 minutes until they have developed a nice brown crust, then flip patties and top each with a slice of cheese and put the pan in the oven. Cook for a further 2 minutes for medium-rare or to your liking.
While patties are in the oven, grill the bacon on the char-grill pan on both sides until nicely charred (2-3 minutes per side).
Meanwhile, steam hamburger buns just until soft, or toast under a hot grill (30 seconds).
Place ½ tbsp of Japanese mayonnaise on the base of each bun, smoothing out with a spoon to cover all areas. Follow with 1 tbsp of caramelised onions and spread out. Top with a patty with cheese, then place 2 slices bacon on top side by side. Place a layer of pickles on top, covering the patty, then, using a squeezy bottle filled with ketchup, top the patty with ketchup starting from the centre and working outwards in a spiral. Finish by placing the bun tops on and serve.
Note Aged beef fat is available from select