Can I freeze this soup?

No, the egg yolks and cream will separate or curdle in the freezer.

Why do I need to temper the egg yolks?

Tempering slowly warms the cold egg mixture so it blends with the hot liquid without scrambling.

How do I remove sand from leeks?

Rinse leeks thoroughly under water or use a salad spinner to remove trapped sand.

What if I overcook the fish?

Poaching takes about 8 to 10 minutes, but start checking at 6 minutes to be safe.

How can I thicken the sauce further?

If the sauce is too thin, simmer it longer or whisk in a small amount of xanthan gum.

Keto Food Ideas

Cod and Leek Waterzooi

Name: Cod and Leek Waterzooi
Prep time: 15 min
Cook time: 18 min
Ingredients: 1 1/2 lb cod fillets, cut into 3-inch pieces; 3 tbsp butter; 2 leeks, white and pale green parts, sliced into thin rounds; 1 carrot, cut into thin matchsticks; 3 cups fish stock; 1 cup heavy cream; 2 egg yolks; 1 bay leaf; 10 black peppercorns, cracked; 3/4 tsp salt, plus more to taste; 2 tbsp chopped fresh dill

⏲ ~33 min total · prep 15 · cook 18 · 4 servings

Recipe Lab · 2026-10-02 · Developed with AI assistance, human-reviewed · Photos: original, AI-generated with real-dish reference

Adapted from Wikibooks Cookbook (CC BY-SA 4.0).

Ingredients

1 1/2 lb cod fillets, cut into 3-inch pieces
3 tbsp butter
2 leeks, white and pale green parts, sliced into thin rounds
1 carrot, cut into thin matchsticks
3 cups fish stock
1 cup heavy cream
2 egg yolks
1 bay leaf
10 black peppercorns, cracked
3/4 tsp salt, plus more to taste
2 tbsp chopped fresh dill

Nutrition

Calculated from USDA FoodData Central reference values, per serving (serves 4).

Per serving
calories kcal	517
protein g	38.4
fat g	35.4
carbs g	11.5
fiber g	1.6
net carbs g	9.9

Instructions

Melt the butter in a wide pot over medium heat. Add the leeks, carrot, bay leaf, and peppercorns and cook 6 to 8 minutes, stirring now and then, until the leeks go limp without taking on any color.
Pour in the fish stock and bring it to a bare simmer. Lower in the cod, cover the pot, and poach 8 to 10 minutes at the laziest possible bubble, until the fish flakes when you press a fork into the thick end.
Lift the cod out with a slotted spoon onto a plate and break it into large chunks. Turn the heat under the pot to low.
Whisk the egg yolks and cream together in a bowl. Ladle in half a cup of the hot broth while whisking, then a second ladleful, so the yolks come up to temperature without curdling.
Stir the tempered cream into the pot and warm it 2 to 3 minutes, until the broth thickens enough to coat a spoon. Do not let it boil; scrambled yolks ruin the texture fast.
Return the cod and any juices to the pot, taste for salt, and stir in the dill. Serve in shallow bowls.

Why this recipe works

Poaching for Moisture: Poaching the cod in the fish stock ensures the protein stays tender and moist without drying out during cooking.
Tempering the Eggs: Tempering the egg yolks with hot broth before adding them to the pot prevents the sauce from curdling or scrambling.
Leek Sweetness: Slicing leeks thinly allows them to soften completely in the butter while releasing their natural sweetness into the broth.

Tips

Check Doneness Early. Remove the cod pieces from the pot as soon as they flake easily with a fork to avoid turning them rubbery.
Clean Leeks Thoroughly. Leeks often trap sand between the layers, so rinse them under running water after slicing to ensure a grit-free texture.
Taste Before Serving. Wait to add the final pinch of salt until after the sauce thickens since the fish stock and cream may vary in salinity.
Use Heavy Cream. Heavy cream provides the necessary fat content for a rich keto sauce while helping the egg yolks emulsify properly.

Serving

This recipe serves 4 people. Serve the soup in shallow bowls to show off the tender cod chunks and the pale green broth. A sprinkle of fresh dill on top adds a bright herbal note that cuts through the richness of the cream. Pair the dish with a crisp green salad dressed with a simple vinaigrette to balance the meal. For a heartier keto option, serve alongside roasted asparagus or steamed green beans to add texture and extra fiber to the plate.

Storage

Store any leftovers in an airtight container in the refrigerator for up to three days. The sauce may separate slightly upon reheating, so whisk the broth vigorously over low heat to reincorporate the ingredients. Do not freeze this dish because the egg yolks and cream will curdle when thawed, resulting in a grainy texture. If you need to prepare it in advance, wait to add the egg yolks and cream until you are ready to serve to maintain the sauce's smooth consistency.

Variations

White Fish: Swap the cod for halibut or tilapia for a similar texture and mild flavor profile.
Vegetable Broth: Use a high-quality vegetable stock instead of fish stock to make the dish vegetarian while keeping it keto-friendly.
Coconut Cream: Replace the heavy cream with full-fat coconut milk for a dairy-free option that adds a subtle tropical sweetness.
Fresh Herbs: Stir in fresh parsley or chives at the end instead of dill for a different aromatic profile.

FAQ

Can I freeze this soup? No, the egg yolks and cream will separate or curdle in the freezer.
Why do I need to temper the egg yolks? Tempering slowly warms the cold egg mixture so it blends with the hot liquid without scrambling.
How do I remove sand from leeks? Rinse leeks thoroughly under water or use a salad spinner to remove trapped sand.
What if I overcook the fish? Poaching takes about 8 to 10 minutes, but start checking at 6 minutes to be safe.
How can I thicken the sauce further? If the sauce is too thin, simmer it longer or whisk in a small amount of xanthan gum.

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Nutrition is calculated per serving from USDA FoodData Central reference values (embedded table); trace ingredients with negligible macros are excluded. Figures are estimates for informational purposes. As an Amazon Associate and affiliate partner, Keto Food Ideas earns from qualifying purchases at no additional cost to you.

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