Cook the pasta according to the instructions on the packet. Cut the tomatoes crosswise and scald with boiling water. Peel the tomatoes and cut into small cubes. Clean, wash and roughly cut the rocket. Wash and pluck the basil. Peel and finely chop onions and garlic. Heat the olive oil in a saucepan, sauté the onions and garlic in it. Mix in the tomato cubes and sauté in them for 5 minutes. Season with balsamic vinegar, a little salt and pepper, fold in the rocket. Drain and drain the spaghetti. Scatter grated parmesan and basil leaves on top.