Chef Klaus
Backfisch mit Kartoffelsalat
Backfisch works when the batter is cold, the fish is dry, and the oil is steady. Miss one of those and you get a wet coat, not a crisp one.
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Kabeljau in Senfsauce
Created by
Northern cod, barely poached, then sauced with its own broth and good German mustard. The fish stays tender because the pot never boils.
Main Dishes
German
Weeknight
Make Ahead
20 min
Active Time
25 min cook•45 min total
Yield4 servings
Kabeljau in Senfsauce belongs to the northern table, strongest along the Baltic coast and on Rügen, where cod, potatoes, mustard, and a little dairy make a proper meal without theatre. It is weeknight food if you have fresh fish, and Sunday food if the potatoes are good and the sauce is made carefully. Das ist kein Bierzelt. The colour here is pale fish, yellow mustard, green dill, and the clean shine of a sauce that hasn't been bullied.
Im Norden anders, im Süden anders. In Mecklenburg and Schleswig-Holstein the sauce is often sharper and lighter, built on the fish liquor and mustard. Further inland you see more cream, sometimes egg, sometimes too much flour. I keep it northern: poach the cod gently, strain the liquor, and make the sauce from that. Weggeworfen wird nichts, the cooking liquid is the backbone of the dish.
The one rule is simple: the poaching liquid must tremble, not boil. Boiling tightens cod into dry flakes and clouds the broth, and then the sauce tastes tired before it begins. Keep it quiet, lift the fish out as soon as it parts under a fork, and add the mustard at the end so its sharpness stays alive. Erst verstehen, dann kochen.
Cod from the North Sea and Baltic was central to northern German cooking through the Hanseatic fish trade, whose ports connected preserved and fresh fish markets from the Middle Ages onward. Rügen and the Mecklenburg coast kept cod and mustard sauce in the everyday kitchen because the dish used what was close at hand: fish, potatoes, dairy, and mustard from a cool-climate larder. The regional split is practical: coastal cooks often keep the sauce lean and sharp on fish liquor, while inland versions soften it with more cream or egg.
The technique, the tradition, and the story behind every dish.
Discover Culinary ExplorerIngredients
thick cod fillets
Quantity
700g
cut into 4 portions
waxy potatoes
Quantity
800g
peeled or scrubbed
water or light fish stock
Quantity
900ml
dry white wine
Quantity
150ml
small onion
Quantity
1
sliced
small carrot
Quantity
1
sliced
bay leaf
Quantity
1
black peppercorns
Quantity
6
parsley stems
Quantity
4
lemon slice
Quantity
1
salt
Quantity
1 teaspoon, plus more to taste
butter
Quantity
35g
plain flour
Quantity
35g
strained cod poaching liquid
Quantity
350ml
cream
Quantity
100ml
German medium-hot mustard
Quantity
3 tablespoons
wholegrain mustard
Quantity
1 tablespoon
lemon juice
Quantity
1 teaspoon, plus more to taste
sugar
Quantity
1 small pinch
white or black pepper
Quantity
to taste
freshly ground
dill
Quantity
2 tablespoons
chopped
| Ingredient | Quantity |
|---|---|
| thick cod filletscut into 4 portions | 700g |
| waxy potatoespeeled or scrubbed | 800g |
| water or light fish stock | 900ml |
| dry white wine | 150ml |
| small onionsliced | 1 |
| small carrotsliced | 1 |
| bay leaf | 1 |
| black peppercorns | 6 |
| parsley stems | 4 |
| lemon slice | 1 |
| salt | 1 teaspoon, plus more to taste |
| butter | 35g |
| plain flour | 35g |
| strained cod poaching liquid | 350ml |
| cream | 100ml |
| German medium-hot mustard | 3 tablespoons |
| wholegrain mustard | 1 tablespoon |
| lemon juice | 1 teaspoon, plus more to taste |
| sugar | 1 small pinch |
| white or black pepperfreshly ground | to taste |
| dillchopped | 2 tablespoons |
Equipment Needed
- •Wide shallow pan with lid
- •Fine sieve
- •Small saucepan
- •Balloon whisk
Instructions
- 1
Cook the potatoes
Put the potatoes in salted cold water and bring them up gently, then cook until a knife slides through without breaking them apart. Starting cold cooks them evenly from edge to centre; drop potatoes into hard boiling water and the outside gives up before the middle is done.
- 2
Build the poaching liquor
Put the water or fish stock, wine, onion, carrot, bay leaf, peppercorns, parsley stems, lemon slice, and salt in a wide pan and simmer for 10 minutes. This short simmer pulls flavour from the vegetables before the fish goes in, so the cod only has to cook long enough to stay tender.
Use a wide pan that lets the fish sit in one layer. Stacking cod makes the lower pieces overcook before the top pieces are ready. - 3
Poach the cod
Turn the heat down until the liquid only trembles, then slide in the cod and cover the pan. Poach 6 to 8 minutes, depending on thickness, until the fish just parts under a fork and is opaque through the centre. Do not boil it. Boiling squeezes out moisture, breaks the flakes, and clouds the liquor you need for the sauce.
- 4
Strain the liquor
Lift the cod to a warm plate and cover it lightly. Strain the poaching liquid and measure 350ml for the sauce. Weggeworfen wird nichts: that clear broth now carries the fish, wine, onion, and bay, and it will taste better than anything from a jar.
- 5
Make the roux
Melt the butter in a saucepan, stir in the flour, and cook it for 2 minutes without letting it brown. This cooks out the raw flour taste while keeping the sauce pale, which is what a northern mustard sauce should be.
- 6
Whisk the sauce
Whisk in the measured poaching liquid a little at a time, then add the cream and simmer gently for 3 to 4 minutes until the sauce coats a spoon. Add the medium-hot mustard, wholegrain mustard, lemon juice, sugar, and pepper off the hard boil. Mustard boiled hard turns dull and bitter; stirred in at the end it stays sharp and clean. Würzen, Fett, Salz zum Schluss.
- 7
Serve the fish
Taste the sauce for salt and lemon, then spoon it over the cod and potatoes and finish with dill. The sauce should be pourable, not paste. If it tightens, loosen it with a spoon or two of the remaining poaching liquid, because the fish should taste of the coast, not of wallpaper paste.
Chef Tips
- •Buy thick cod from a fishmonger you trust, or use fresh Baltic Dorsch when you can get it. Thin tail pieces overcook fast, and no sauce will repair dry fish.
- •Use German mittelscharfer Senf, medium-hot mustard, for the base. Dijon is sharper and leaner, Bavarian sweet mustard is wrong here, and jarred ready-made mustard sauce is not a shortcut. Nicht aus dem Glas.
- •Keep the leftover poaching liquid. Strain it, chill it, and use it the next day for fish soup or to loosen more sauce. Weggeworfen wird nichts.
- •Serve with boiled potatoes and cucumber salad. The potatoes catch the sauce, and the cucumber brings the cool bite this pale northern plate wants.
Advance Preparation
- •The poaching liquor can be simmered and strained up to 24 hours ahead, then chilled. Bring it back to a gentle tremble before the cod goes in.
- •The potatoes can be cooked earlier the same day and rewarmed in a little salted water. The cod should be poached close to serving, because reheated cod turns dry fast.
- •The finished sauce can be made 1 day ahead and warmed gently, loosened with reserved poaching liquid. Add the mustard fresh at the end if you want the cleanest bite.
Frequently Asked Questions
Nutrition Information
1 serving (about 470g)
Calories
480 calories
Total Fat
17 g
Saturated Fat
9 g
Trans Fat
0 g
Unsaturated Fat
7 g
Cholesterol
120 mg
Sodium
700 mg
Total Carbohydrates
44 g
Dietary Fiber
4 g
Sugars
3 g
Protein
38 g
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