Flash-roasted lamb fillet with soya marinade

1. Trim lamb of fat and sinews, and dry with paper towels. Place a large pan over a high heat, and pour in the vegetable oil. When the pan is really hot, sear the lamb quickly but evenly – around 5 minutes in all. Place in a bowl which will hold it snugly.
MARINADE
2. Mix all liquid ingredients (use the juice of 1/2 lemon, if lime is unavailable), add peeled and roughly chopped garlic, season with pepper and pour over the lamb. Marinate for at least 20 minutes. Once cool, this can be covered and refrigerated for up to 24 hours.
3. When you’re ready to cook, remove lamb from fridge (if applicable). Put lamb on a rack which will go in your roasting tin and leave to drain for a few minutes. Bake at 230 ºC at top of oven for around 20 minutes (medium-rare) or 25 minutes (well done). Cover loosely with foil and set aside for 5 minutes before slicing thinly and serving. The hot oven can be used for baked potatoes and braised celery, both perfect partners for this dish.
Serves 4.