Wash fish and cut into pieces, cut squid into rings. Remove the shrimps from their shells up to the tail. Clean, wash and slice the celery. Peel and chop carrots.
Peel and roughly chop the onions and garlic. Crush with peppercorns in a mortar. Stir in 2 tablespoons of olive oil. Chop the tomatoes in a tin. Heat the remaining oil and fry the celery and carrots in it.
Douse with white wine. Add the garlic mixture, tomatoes and bay leaf and cook for about 10 minutes. Cook the prepared fish ingredients for about 10 minutes. Wash the thyme, dab dry and remove the leaves.
Season fish pot with salt and pepper and serve sprinkled with thyme.