Peel the onion and cut into strips. Wash the meat, dab dry and cut in half crosswise. Season with salt and pepper and spread 1 teaspoon of pesto on each. Roll up and fix with wooden skewers.
Heat the oil in a frying pan and fry the rolls for 5-8 minutes while turning them. Remove, keep warm and fry the onion in the frying fat until transparent. Dust with flour, add tomatoes, bring to the boil and season to taste with salt, pepper and sugar.
Meanwhile, prepare the pasta in boiling salted water according to the instructions on the packet. Arrange noodles, sauce and rolls on plates. Garnish with basil.