Fish Braised on Onion (Carp or Catfish)

Preparation

1. Preparing the Fish

Rinse the fish fillets under cold water, pat dry with paper towels and cut into 8–10 cm portions. Season with salt and pepper on both sides. Leave for 10 minutes to allow the salt to penetrate.

If the fillets have skin, leave it on — it holds the flesh together during braising. If using a whole fish rather than fillets, cut into steaks (tranches) about 3–4 cm thick.

2. Braising the Onion

In a wide, deep pan (or a lidded frying pan) heat the oil over medium-high heat. Add all the onion at once. Stir and salt lightly (salt helps the onion release moisture).

Braise the onion over medium-low heat for 20–25 minutes, stirring every 5 minutes. The onion should soften completely, turn golden-yellow to light brown and become almost translucent — it must not burn, only caramelise gently. This is the key step that determines the flavour of the dish.

After 15 minutes, add the chopped garlic and bay leaves and continue braising for another 5 minutes.

3. Adding the Spices and Tomato

Remove the pan from the heat momentarily and add the sweet red paprika — paprika must not be added directly to very hot oil as it burns and turns bitter. Stir and return to the heat.

Add the diced tomato and pour in the white wine. Stir, increase the heat and cook for 5 minutes until the alcohol evaporates and the sauce thickens slightly. Taste the salt and adjust.

4. Braising the Fish

Carefully arrange the fish portions in the pan, nestling them gently into the onion sauce. The fish should be partially submerged in the sauce — if the sauce is too thick, add 50–100 ml of warm water.

Cover with a lid and braise over low heat for 15–20 minutes. Do not stir — this would break up the fish. Instead, periodically shake the pan gently in a circular motion. The fish is done when it flakes easily with a fork and the flesh is completely white with no translucent parts.

5. Resting and Serving

Remove the pan from the heat and leave covered for 5 minutes — the fish settles and the sauce becomes more unified. Remove the bay leaves.

Serve in deep bowls or bring the pan directly to the table. Scatter generously with fresh parsley. Ideal accompaniments: polenta (kačamak), jacket potatoes or fresh bread for mopping up the rich onion sauce.

Tips

Why so much onion: the onion in this recipe is not a side dish — it is the sauce. Long braising transforms sharp raw onion into a sweet, creamy coating that perfectly complements the rich river fish. Do not reduce the quantity — 4 large onions to 800 g of fish is the right ratio.

Carp vs. catfish: carp has fattier and sweeter flesh but more small bones. Catfish has firmer flesh with fewer bones and a more neutral flavour. For children and elderly guests who find it hard to remove bones — catfish is recommended. For the traditional flavour of childhood — carp.

Wine in fasting cooking: white wine adds juiciness and acidity that balances the sweetness of the onion. If not using wine, substitute with 100 ml of water and 2 tablespoons of lemon juice — the effect is similar.

Storage: fish braised on onion keeps for up to 2 days refrigerated. Reheat slowly over low heat with a little water, or in the microwave at 50% power. The flavour actually improves the next day once the spices have fully infused.

For Slava gatherings: this dish is ideal for the Slava table during fasting periods as it can be fully prepared a day ahead and gently reheated just before guests arrive — even better for the waiting.