A classic and delicious dish from Venice is pesce in saôr, which does not mean ‘sour’ fish but ‘flavored’ fish (saôr comes from ‘sapore’). The recipe was invented in Venice as a way to preserve fish, and even though we have refrigerators nowadays we still make it because it is so tasty!
In this modern version I’ve made two changes to the classical recipe: I’ve used mackerel rather than the more usual white fish (such as cod or hake) and I’ve cooked the fish sous-vide. When you use white fish, the subtle flavor of the fish will be overpowered by the marinade. Mackerel has a nice but stronger taste that you can still taste. The creaminess of the mackerel goes well with the sweet & sour marinade. By cooking sous-vide, the fish will be more tender and juicy than when it’s pan-fried.
This dish needs to marinate at least 6 hours, but 24 hours is better to let the flavors develop. You can also make it without sous-vide and with all kinds of fish, even jumbo shrimp.
For 4 servings as antipasti
Fillets of 2 fresh mackerels, about 400 grams (0.9 lbs) [Ask your fishmonger to fillet the mackerel and to remove the skin.]
2 large onions
300 ml (1 1/4 cup) dry white wine
120 ml (1/2 cup) good quality white wine vinegar
2 Tbsp olive oil
4 Tbsp white raisins
2 Tbsp pine nuts
1 bay leaf
salt and freshly ground white pepper
Step 1: marinade
Start with the marinade. Soak the raisins for 10 minutes in warm water. Roast the pine nuts for 10 minutes in the oven at 150C/300F. Slice the onions.
Heat 2 Tbsp olive oil in a frying pan. Cook the onions over low heat until golden, around 10 minutes. For a sweeter flavor you could cook as long as 2 hours!
Add vinegar, wine, raisins (drained), pine nuts and bay leaf. Simmer for 15 minutes over low heat.
Season white salt, freshly ground white pepper and cinnamon. Let cool.
Step 2: fish
Prepare the fish while the marinade is cooling down.
Each fillet will still have vertical bones in the middle. With a short knife, cut in a straight line along both sides of that layer of bones to remove it (as shown).
Season the mackerel fillets with salt and freshly ground white pepper. Seal in a bag and cook sous-vide for 15 minutes at 50C/122F. Cool in ice water until the marinade is ready.
[As an alternative for sous-vide, flour the fish fillets and fry them in a non-stick frying pan for a few minutes on each side. Let cool on paper towels and pat dry with paper towels to remove as much oil as possible.]
Step 3: marinate
Marinate the fish in a wide shallow dish that is big enough for all of the fish fillets in a single layer. Put half the onions on the bottom, then a layer of fish and end with the remaining onions. Add all of the moisture from the marinade as well. Sprinkle with chopped parsley. Cover and refrigerate for 6-24 hours.
Step 4: serve
Take the dish out of the refrigerator about an hour before serving to let the fish come to room temperature.
Serve the fish with the onions and marinade on top with a slice of lemon.
Because of the sweet tones in this dish, it’s good with a complex round white that it is dry but not bone-dry. Grape varieties such as pinot bianco/blanc/weissburgunder, pinot grigio/gris/grauburgunder or dry muscat from Alto Adige, Alsace or Germany could all work out really well.