Warm roast lamb salad

Method

1. Preheat the oven to 220°C/fan 200°C/gas 7. With the tip of a small, sharp knife make slits all over the lamb. Insert a sliver of garlic and a sprig of rosemary into each slit. Weigh the lamb and calculate the cooking time. Cook for 20 minutes, then reduce the oven temperature to 190°C/fan170°C/gas 5 and roast for a further 20 minutes per 450g. This will give a slightly pink lamb. Add an extra 20 minutes if you like it medium.
2. Meanwhile, cook the potatoes in boiling, salted water for 10-15 minutes until tender. Drain and spill into a roasting tin, drizzle with 2 tablespoons of oil and season. Roast for 30 minutes before the lamb is done.
3. Cook the beans in boiling, salted water, drain and refresh under cold running water. Drain again and put aside.
4. Make the dressing: whisk together the remaining oil, vinegar, sugar, mint and plenty of seasoning.
5. Take the lamb and potatoes out of the oven. Leave the lamb to rest for 15 minutes and the potatoes to cool (they both only need to be just warm when served). Slice the lamb and put on to a plate. Put the tomatoes, salad leaves, green beans and warm potatoes into a large bowl and toss well. Drizzle with enough dressing to coat and toss again. Add the lamb to serve. Put the rest of dressing into a jug for everyone to help themselves.