Glazed onglet steak with brown butter mash, crispy shallots and madeira

Method

1. Put the sliced shallots and the flour in a small bowl with plenty of salt, then rub the flour into the shallots to coat. Heat the oil in a small frying pan until it shimmers, then throw in a piece of shallot – if it sizzles the oil is hot enough. Cook the shallots in 2 batches over a high heat until golden and crisp. Remove with a slotted spoon to a plate lined with kitchen paper and set aside.
2. For the mash, put the potatoes in a large pan of salted boiling water and cook for 15-20 minutes until very tender. Drain in a colander and leave to steam dry for 5 minutes, then pass through a ricer until very smooth (if you don’t have a ricer and still want restaurant-smooth mash, push the potatoes through a fine sieve using a dough scraper or the back of a large spoon).
3. Melt the butter for the mash in a saucepan then, once melted, turn up the heat and bubble until the milk solids turn brown and the butter smells biscuity. Immediately pour the milk into the pan to stop the butter burning, then add it to the potatoes and mix in with a generous pinch of salt until smooth. Set aside.
4. To cook the steak, heat a large heavy-based frying pan over a high heat. Rub the steaks with oil and season well with salt. Once the pan is very hot, add the steaks and fry for 2½ minutes on one side, pressing the steaks down into the pan with a spatula, so they colour well, then flip them and fry for 2½ minutes on the other side. After around a minute and a half on the second side, add the butter, thyme and garlic to the pan. Once the butter melts, tip the pan so the butter pools, then keep spooning it over the steaks as they cook. Once they’ve had their cooking time, remove the steaks to a plate, cover loosely with foil and leave to rest.
5. Put the pan back over a high heat, pour in the madeira and use a wooden spoon to scrape up any browned bits from the bottom of the pan. Bubble the madeira to reduce and form a sauce with the butter (give it a whisk if it doesn’t come together), then taste and season with more salt and plenty of black pepper. Strain into a jug. Gently reheat the mash. Slice the steaks and stir the resting juices into the sauce. Put swirls of mash on each plate, top with the steaks, a drizzle of the sauce and a tangle of crispy shallots, then serve with steamed greens or a salad.