Roughly chop the basil except for a few leaves for garnish. Finely chop with garlic, pine nuts and parmesan in the universal chopper. Add 70 ml of oil, salt / pepper and stir in.
Clean, wash and quarter the tomatoes. Peel the onion and cut into wedges. Heat the remaining olive oil in a large pan and fry the onion wedges in it. Salt and pepper. Add the tomatoes and cook covered for approx. 6-8 minutes.
Turn carefully in between and season to taste again. Scatter the sheep`s cheese and olives on top and let simmer for another 3-4 minutes. Arrange the braised tomatoes on plates and spread the pesto over them in small heaps. Serve the rest of the pesto separately.