1 Rinse the fillets under running cold water, pat dry, divide it into serving pieces and place in a bowl. Add 3 tablespoons of lemon juice, stir and let sit covered for about 30 minutes in the refrigerator. In the meantime, peel the potatoes, carrots and onions and cut into cubes. Also roughly chop the tomatoes. Rinse, dry and slice the celery. Peel and press the garlic. Rinse the parsley, shake dry and finely chop. Place the olive oil in a large saucepan and saute the potatoes, carrots and onions. Add the tomatoes, celery, garlic, parsley and bay leaf. Fill with water and season with salt and pepper. Put in a pot with a lid, cover and let the vegetables simmer over low heat for about 30 minutes.
2 Then add the fish fillets with the soup, cover and simmer for about 15 minutes. If necessary, add a little water. When the fish is cooked, add the shrimp, boil and season the soup with salt, pepper and remaining lemon juice. Serve immediately.