Boil up about 1/2 litre of water with broth in a small pot. Cook the noodles for about 10 minutes. Halve and slice the onions. Wash and halve the tomatoes. Wash the lettuce, drain and cut into large pieces. Wash the basil, remove the leaves and cut into fine strips. Mix vinegar, 2-3 tablespoons of pasta stock, salt, pepper and a little sweetener.
Whip the oil into it. Stir in basil. Drain noodles, rinse and drain well. Mix with the tomatoes, onions and salad. Spread basil dressing over it, let it soak well. Season pasta salad with salt and pepper and serve. Garnish with basil if desired.