Seared tuna and vegetable pasta salad

Mix olive oil and crushed peppercorns in a bowl. Coat each piece of tuna with the mixture and set aside. Bring 2 saucepans (1 large) of salted water to the boil. Add carrots to the smaller pan and cook for 4 minutes. Add beans and courgettes and cook for a further 2 minutes. Then add asparagus, cook for 3 more minutes and drain. Add pasta to the large saucepan, stir and return to the boil. Cook for 12-15 minutes until al dente (firm to the bite). Drain and reserve 150 ml of the water.
Heat a heavy-based pan until just smoking. Add the tuna pieces and sear for 2 minutes on each side, so the tuna is still pink in the centre. Remove tuna and set aside. Put sour cream into a saucepan and heat gently until hot. Add vegetables and season to taste. Toss in the pasta, adding a little pasta water to loosen, if necessary. Transfer to a large serving bowl. Thinly slice tuna and gently toss into the salad. Season and serve. Serves 4.