Method
You need to start your burger prep at least 5 hours before you want to eat.
- For the pickled shiitake mushrooms, soak the shiitake mushrooms in boiling water until softened for 3-5 hours. Lift the mushrooms from the steeping liquid (reserve the liquid), discard the stalks and cut the caps into 3mm slices. Strain and reserve 50ml of the steeping liquid, then pour into a small pan. Add the mushroom caps, caster sugar, soy sauce, cider vinegar and root ginger. Bring to a simmer and cook for 30 minutes, stirring occasionally, then remove from the heat and leave to cool. Strain into a sterilised jar (discarding the ginger). Seal and leave in the fridge to pickle for at least an hour (although they’re better after 1 week).
- For the Gentleman’s relish butter, put the anchovy fillets, butter, cayenne pepper, nutmeg, black pepper and ground cinnamon with the lemon juice, Worcestershire sauce and water into a blender or food processor and whizz until smooth. Put a sheet of cling film onto the work surface and spoon the butter along the edge nearest you, then use the cling film to roll it into a tight log, twisting the ends to seal. Chill in the fridge for an hour, or until firm, before using.
- Heat the oven to 110°C/90°C fan/gas ¼. Put the tomato slices on a baking tray and cook for 4 hours to dry out, turning halfway. Set aside.
- Next, make the parmesan tuiles: turn the oven up to 180°C/160°C fan/gas 4 and line 2 trays with non-stick baking paper. Grate the parmesan (see tips) into 4 equal round piles. Bake for 5-7 minutes until melted and golden. Remove and leave to cool on the trays.
- For the umami sauce, mix the mayo, mustard, ketchup and soy in a bowl.
- Heat the olive oil in a small frying pan over a medium heat and fry the onion with a pinch of salt for 8-10 minutes until softening, then set aside.
- Meanwhile, form 4 loose patties out of the mince. Season the patties with the smoked sea salt flakes, heat a griddle pan until smoking hot and split and toast the burger buns. Grill the burgers for 4 minutes on each side until medium rare, or longer for well done.
- Still on the griddle, top each burger with fried onion, pickled mushrooms and 1-2 slices of the gentleman’s relish butter, followed by a slice of cheese. Spread both sides of the buns with the umami sauce, then put a lettuce leaf and some dried tomato slices on the base. Put a stacked burger on top, followed by a parmesan tuile and finally the bun top.
This recipe is from Prime: The Beef Cookbook by Richard H Turner (£25; Mitchell Beazley).