My fish soup, as I learned to make it from my mother, is time consuming, but wonderful, although not really a glorious bouillabaisse.
Its flavor depends on the incredible freshness of the simple fish I use, which in most cases is almost alive when I get it from the caïque, less than a few hours out of the water.
I usually make the broth the day before, refrigerate it, then finish the soup the next day.
In kakavia, the traditional fish soup of the Greek fishermen, all kinds of small fish that cannot be sold, the cheapest kinds you find that are not suitable for grilling or frying, are boiled for with plenty of olive oil and a few vegetables and herbs, until the flesh almost falls from the bones and the vegetables are very tender. Then all trhe ingredients of the pot are strained, and fish witrh vegetables served in a platter along with the broth which is dressed with more fruity olive oil and lemon juice. I heard that in Provence the somewhat scarry weevers are considered ideal for the bouillabaisse; we also use them in this simple traditional fish soup.
In my version, if a couple of larger fish are available, I carefully fillet them, drop the bones in the pot, and refrigerate or freeze the fillets, to be added in the soup at the very end since they need no more than 2-3 minutes cooking.
Between kakavia and bouillabaisse
I strain the broth from the small fish and after I remove all bones and heads, I pass it again through a very fine sieve to make sure all scales and small bones are removed. Then I sauté leeks or onions and two-three coarsely chopped garlic cloves in plenty of olive oil, then add potatoes and other vegetables, and finally the fish broth, cook until the vegetables are tender.
I know that some fish mongers sell fish carcasses which can be boiled to make the stock. Below is my basic fish soup recipe, but you can certainly play around with the quantities and ingredients adding more onions if you have no leeks, celery leaves instead of root etc. Taking inspiration from the bouillabaisse of Provence, I also add a pinch of saffron.
My mother used to mash coarsely in the food mill all the vegetables at the end, but I like to keep a few pieces of potato, zucchini, and peppers, to serve in the soup plates together with the fish fillets.
NOTE that you could probably use clam juice, or a good quality ready made fish stock if available, and skip the first part of boiling the fish and vegetables. But I wouldn’t use the Japanese shaved, dried tuna, dashi, or combu. In my opinion their taste is somwhat too prominent and very different from the delicate flavor of small fish and fish bones. But, during the busy summer months many Greek taverns use them…
The FISH BROTH
3 ½ pounds small and/or medium fish, gutted and scaled –the larger fish filleted and the fillets refrigerated or frozen
3 cups dry white wine
A small celery root with leaves, or 3 large celery stalks
2 medium zucchinis, halved lengthwise, and/or 1-2 pieces squash
Most green part of 2-3 leeks, or 2 medium onions quartered
1 tablespoon allspice berries, bruised in a mortar
1-piece fresh ginger, about 2-inches, halved lengthwise
1 piece star anise
1 tablespoon anise seeds, coarsely ground in a mortar
About 1 ½ teaspoon sea salt, or more to taste
FINISHING the Soup
½-2/3 cup olive oil
1 large onion, or 2 leeks thinly sliced
2-3 large garlic cloves, sliced
2 medium potatoes peeled and cut into chunks
1 medium zucchini halved lengthwise; each piece cut into 3
1 red and 1 green bell pepper, seeded and quartered
2 medium tomatoes, halved to remove the stem, then each piece quartered
1 pinch saffron soaked in ¼ cup boiling water
1-2 teaspoons Aleppo pepper or red pepper flakes, to taste
Juice of 1 lemon or more, to taste
A handful flat-leaved parsley leaves
Lemon halves or quarters
Fruity olive oil for drizzling
In a large pot place the fish, all vegetables and spices, add the wine and water to just cover the lot, and cook in medium-high heat for about 45 minutes or more, until the flesh almost falls from the fish bones and all vegetables are very tender.
Strain the broth, setting aside the vegetables, after checking they are free from fish bones or scales. Press and discard all other solids, then pass again the broth through a very small sieve. Set aside.
To finish the soup: In a skillet warm the olive oil and sauté the leeks or onion and the garlic until translucent, then add this to the rest of the vegetables and the fish broth; bring to a slow boil. Cook in medium-high heat until all vegetables are tender. Remove half of the vegetables with a slotted spoon and set aside, then pass the rest through a food mill.
Return the broth to the pot, add the saffron, Aleppo or pepper flakes and lemon juice, and taste to correct the flavor. Add the fish fillets and the reserved vegetable pieces, and boil in high heat for about 3-4 minutes, or until the fish fillets are cooked, depending on their size.
Add freshly squeezed lemon juice, and either serve the soup in bowls or bring the pot to the table.
Serve a piece of the fillet and some of the vegetables along with the delicious broth, decorating with parsley sprigs and bringing extra lemon and olive oil to the table.