Clean and wash the salad, drain well and pluck into bite-sized pieces. Clean and wash the tomatoes and peppers. Cut tomatoes into slices, peppers into small pieces. Peel onion and cut into thin rings.
Clean, wash and cut the spring onion into rings. For the vinaigrette season vinegar with salt, pepper and 1 pinch of sugar. Whip olive oil into it. Wash the basil, dab dry and chop finely except for something to garnish and add to the salad dressing.
Place the prepared salad ingredients in a bowl, pour the vinaigrette over them and mix loosely. Serve garnished with the remaining basil.