Beef Fillet with Potato Rösti and Wild Mushroom Sauce

Heat the oven to 200°C/180°C fan. Squeeze the grated potato in a clean tea towel until as dry as possible, then mix with the egg yolk, crème fraîche, a pinch of salt and plenty of black pepper.

Warm a little butter and oil in a non-stick frying pan. Shape the potato mixture into two neat rösti cakes and fry for 4–5 minutes on each side until golden, then transfer to a baking tray and keep hot in the oven.

Put the halved shallots in the same tray with a knob of butter and the thyme. Roast for 15–20 minutes until soft and lightly caramelised.

For the sauce, soften the finely chopped shallot in a small pan with a little butter. Add the garlic, pour in the Madeira and bubble until reduced by half, then add the stock and simmer until glossy. Whisk in a small knob of butter and stir through the tarragon.

Pat the beef dry and season well. Sear in a hot frying pan with the oil for 2–3 minutes on each side for medium-rare, or longer to your liking. Rest on a warm plate for 5 minutes.

Fry the wild mushrooms in the beef pan with a little butter until browned and tender. Wilt the spinach briefly in a separate pan, then season and drain away any excess liquid.

Sit each rösti on a warm plate, spoon over the spinach and mushrooms, then top with the rested beef fillet. Add the roasted shallots and finish with the wild mushroom Madeira sauce.