Clean and wash the vegetables. Dice the zucchini, eggplants and peppers. Scald tomatoes hot, peel and also dice them. Peel and finely dice onions and garlic.
Heat the oil in a pot. Brown the onions in it. Add vegetables and sauté. Season with salt, pepper, rosemary and basil and pour on the stock. Braise in a closed pot for 20-25 minutes.
Wash and chop the parsley and finally sprinkle over the ratatouille.