This recipe must be started 1 day in advance.

To make the demi-glace sauce, roast the beef bones and veal trimmings in a hot oven until deeply browned.

Coat the vegetables in tomato paste and roast in a separate tray until browned.

Drain excess fat off the meat and place in a large stockpot with the roasted vegetables.

Place the empty tray on the stove, add the red wine and cook gently, scraping up browned bits.

Cook until wine has reduced to a glaze, then add to the pot.

Add enough water to cover all ingredients. Simmer for 8 hours, regularly skimming the foam off during the first hour.

Strain, discard solids and return the liquid to the heat. Simmer until reduced by half. Season with salt, pepper and soy sauce to taste.

Makes approximately 1L but can be frozen. Refrigerate until needed.

To make the croquettes, place the potatoes in a pot and cover with plenty of salted water.

Bring to the boil and cook for 15 minutes, or until the tip of a knife pierces the potato with ease.

Meanwhile, heat 2 tbsps of oil in a large frypan and gently fry the Wagyu, shiitake, onion and carrot.

Cook until onion is soft, making sure it doesn’t colour.

Add the sugar, sake and soy, bring to the boil and simmer for 10 minutes to melt the sugar and allow everything to infuse.

Taste and add more soy, salt or sugar as required. It should be very strongly flavoured at this point.

Drain the potatoes and stand for 5 minutes to steam off excess moisture.

Transfer to a large bowl and mash lightly to create a homogeneous mixture while retaining large chunks of potato.

Add beef mixture and use a spatula to gently fold through the potato, making sure not to break the chunks too much.

Spread on a tray and allow to cool to room temperature.

Prepare a tray lined with baking paper. With gloved or slightly wet hands, shape the mixture into 70g ovals and place on the tray.

Do not stack because they’ll stick together. Cover and refrigerate for a few hours, or overnight, to firm up.

Prepare 4 trays or bowls to crumb the croquettes. In the first, place the flour. In the second, the egg. The third, the Panko.

Line the final tray with baking paper for the completed crumbed croquettes.

Crumb the croquettes by first coating them in the flour, then the beaten egg, followed by the Panko, shaking off the excess after each coat.

The croquettes at this point can be frozen for up to 1 month.

Heat oil to 180°C in a large saucepan or deep-fryer.

Deep fry croquettes for 3 minutes or until a skewer inserted into the centre comes out hot.

Drain thoroughly and serve with lots of shredded cabbage, the warmed demi-glace sauce and Japanese mayonnaise.