Valentine Warner's roasted lamb neck fillet with garlic sauce

To make the garlic sauce, peel the skins off the garlic and discard. Melt the butter with the oil in a small saucepan. Add the garlic and sliced onion. Cook over a low heat for 5 minutes until the onion is softened but not coloured, stirring occasionally.

Stir in the sugar, vinegar and white wine. Bring to a gentle simmer, cover loosely and cook for 20-30 minutes, stirring occasionally, until both the garlic and onion are soft.

Put a metal-handled frying pan small enough to go in the oven on a medium heat and let it get very hot, but not smoking. Meanwhile, trim the lamb necks of any particularly hard pieces of fat or sinew and season with plenty of salt, ground black pepper and thyme. Roll the lamb gently on a side plate covered in the oil. Heat the oven to 220C/fan 200C/gas 7.

Add the lamb to the pan, where it should brown immediately and cook the fillets for 3-4 minutes on one side only. Turn them over and then put into the oven for a further 8 minutes.

Remove the pan from the oven – take care, as the handle will be extremely hot. Cover the meat with foil and a tea towel. Leave to rest for 10 minutes.

While the lamb is resting, stir the cream into the garlic and onion. Take off the heat and blitz with a hand blender until smooth. Return to the heat and warm through until bubbling gently. Season.

Pour the sauce onto four warmed plates. Carve the lamb into diagonal slices and place on top of the sauce.