Peel, wash and quarter the potatoes. Peel onions and garlic and chop finely. Wash, clean and chop aubergines, zucchini, celery and tomatoes. Wash and chop the oregano, except for something to garnish.
Heat 2 tablespoons of oil. Fry the potatoes for about 5 minutes while turning them and season with salt. Fry onion and garlic briefly. Add remaining oil. Add aubergines and fry. Add zucchini, celery, tomatoes and stock.
Season with chili and chopped oregano. Cover and cook for about 30 minutes at medium heat. Season again and serve garnished with olives and the remaining oregano.