Orange trees planted in public plazas in Spain, such as the enchanting Patio de los Naranjos adjoining the cathedral in Sevilla, are the bitter orange, the same kind used for marmelade. The peel of the fruit is bitingly bitter; the juice is mouth-puckeringly sour. The bitter orange is used as rootstock for growing sweet oranges and is also grown for its decorative beauty and the heady perfume of orange blossoms in springtime.
Affectionately called cachorreñas, bitter oranges are used in quite a few Andalusian dishes. The following recipe is for an unusual fish soup that is subtly flavored with the sour juice. At its simplest, the soup is concocted with small bits of salt cod (bacalao) and served as a starter. I like to turn it into a main course, using big pieces of fresh hake. You could use cod or haddock instead of hake or any flavorful rock fish. If possible use head, bones and trimmings to make stock.
In the U.S., look for bitter oranges at Hispanic markets during winter months. (December-March). If they are not available, use half orange juice and half lemon juice in this recipe.
Fish Soup with Sour Orange
This recipe comes from MY KITCHEN IN SPAIN, the book (HarperCollins).
2 pounds whole hake, filleted, bones reserved (or 1 ½ pounds fillets)
2-inch strip of orange zest, blanched in boiling water
1 tablespoon salt
sprig of parsley
1 small green pepper, seeds removed
1 bay leaf
1 cup lightly packed bread crumbs (2 ounces)
3 tablespoons olive oil
1 clove garlic
1 teaspoon pimentón (paprika, not smoked)
¼ teaspoon ground cumin
½ cup juice from bitter oranges (or orange and lemon juice)
thinly sliced orange for garnish
chopped scallions for garnish
Place the fish head, bones and trimmings in a soup pot and cover with 6 cups of water. Add the orange zest, salt, parsley, onion, whole tomato, pepper and bay leaf. Bring to a boil and simmer 30 minutes. (If head and trimmings are not available, cook the zest, parsley, onion, tomato, pepper and bay in water for 15 minutes.)
Strain the liquid into another pan. Discard the fish heads and bones, parsley, zest and bay leaf. Remove and discard the tomato core. Place the tomato, onion and pepper in a blender with ½ cup of the reserved liquid. Sieve the puree to remove skins and seeds. Return to blender with the bread crumbs, oil, garlic, pimentón and cumin. Blend until smooth.
Add the tomato mixture to the soup. Bring to a boil and cook 5 minutes.
Cut the fish fillets into 4 pieces. Add them to the soup and cook 5 minutes more. Hake is very delicate, so take care not to break it up. Stir in the orange juice and cook 1 minute more.
Serve the soup into 4 soup bowls, each with a piece of fish, garnished with a thin slice of orange and a sprinkling of scallions.
Cachorreñas-- Fish Soup with Sour Orange