In a large stew pan, heat the onions with olive oil and garlic at slow pace
Add tomatoes and tomato concentrate, raise heat to moderate
Add 12 cups water, herbs (bouquet), orange peel, and cleaned fish (red mullet, conger eels, any other small fish and small crabs) in the stew pan. Add salt and pepper. Cook uncovered at moderate heat for 20 to 25 minutes
Remove the bouquet of herbs and the orange peel. Taste and if needed add more seasoning
Put the John Dory and the monkfish. Add saffron. If needed add water to make sure that fish are covered.
Boil for 10 minutes. Add red gurnard and scorpion fish. Boil again for 6 minutes.