Seafood casserole is exactly the kind of dish I make when I'm craving something a bit "bistro-style," comforting, but without spending all afternoon in the kitchen. I've made it a lot after a weekend at the seaside, trying to recreate that rich, coating white wine sauce, with a subtle gratin that gives just the right amount of crispness on top.
What I love about this dish is the balance: the seafood is quickly seared to preserve its texture (especially the scallops), and a classic sauce is built from a shallot and white wine base with fish stock, then thickened with a light roux. Nothing complicated, but you just have to follow the order and avoid overcooking the seafood.
To stay true to the traditional style, I keep the essentials: button mushrooms, cream, a squeeze of lemon, and a touch of mustard (optional, but it adds a bit of a kick). And to keep with the season, I add leek and carrot: they bring a creamy texture and a touch of sweetness that works beautifully with the fish stock.
You can serve this with rice, homemade mashed potatoes, or simply some good bread for dipping (that's often the first thing to disappear). And if you're cooking for friends: prepare everything in advance, keep it chilled, and then brown the top at the last minute. You'll look very organized without making things complicated.
Seafood casserole
4
parts20
minutes35
minutes494
kcal55
minutesA creamy casserole, perfectly browned, with seared seafood and a white wine sauce thickened with fish stock. A comforting dish that evokes the flavors of the coast, ready in under an hour.
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Ingredients
400g mixed seafood (peeled prawns, cooked shelled mussels, squid rings)
200g of scallops
250g of button mushrooms
1 leek (the white part)
1 carrot
2 shallots
1 garlic clove
20g of butter
1 tablespoon of olive oil
20g of flour
15 cl of dry white wine
25 cl of fish stock (or fish broth)
20 cl of fresh cream (or whole liquid cream)
1 teaspoon of Dijon mustard (optional)
1 tablespoon of lemon juice
40g cheese of grated Gruyère
1 tablespoon of chopped flat-leaf parsley
Fine salt, freshly ground pepper
1 pinch of Espelette pepper (optional)
Preparation steps
- Preheat the oven to 220°C (grill if you have one, otherwise conventional heat). Lightly butter 4 ramekins (or a gratin dish).
- Prepare the vegetables: finely slice the white part of the leek, dice the carrot into a very small brunoise (small cubes), slice the mushrooms. Finely chop the shallots and mince the garlic.
- Drain the seafood well. If your scallops are large, cut them in half lengthwise for more even cooking.
- In a large frying pan, heat the olive oil with a knob of butter. Sear the scallops for 45 seconds to 1 minute per side, just until they are colored. Season with salt and pepper, then transfer to a plate (do not leave them in the pan, otherwise they will continue to cook).
- In the same pan, add the remaining butter. Sauté the shallots and garlic for 1 minute, then add the leek and carrot. Cook over medium heat for 5 minutes, stirring occasionally (the goal is to soften without browning).
- Add the mushrooms and turn up the heat slightly: they will release their water. Cook for 5 to 7 minutes, until almost all the liquid has evaporated. Season with pepper.
- Deglaze with white wine: pour it in all at once, scrape the bottom of the pan well, then let it reduce for 2 to 3 minutes (we want to remove the alcohol and concentrate).
- Sprinkle the flour over the vegetables. Mix for 1 minute: this is your quick roux, it will thicken the sauce without lumps.
- Pour in the stock little by little while stirring (like a béchamel sauce, but more relaxed). Let it simmer for 3 to 4 minutes: the sauce should coat the back of a spoon.
- Lower the heat, add the cream, mustard (if using), lemon juice, and parsley. Taste and adjust the salt and pepper (go easy on the salt if your seafood is already salty).
- Add the seafood mix (prawns, mussels, squid) to the sauce and heat for 1 to 2 minutes, just to warm through. Remove from the heat, add the reserved scallops, and mix gently.
- Divide the mixture among the ramekins. Sprinkle with grated Gruyère cheese (and a pinch of Espelette pepper if you like).
- Bake for 6 to 8 minutes, just long enough to brown and bubble around the edges. Serve immediately, piping hot.
📊 Nutritional Information
1 serving (approx. 360g)
| Nutrient | Value |
|---|---|
| Calories | 494 kcal |
| Proteins | 35g |
| Carbohydrates | 22g |
| including sugars | 7g |
| Lipids | 22g |
| including saturated fatty acids | 13g |
| Fibers | 3 g |
| Sodium | 980mg |
| Vitamins | |
| Vitamin B12 | 170% AJR |
| Vitamin B3 | 45% AJR |
| Vitamin A | 35% AJR |
| Minerals | |
| Selenium | 95% RDA |
| Zinc | 25% AJR |
| Phosphorus | 40% AJR |
* RDA = Recommended Daily Allowance
📝 Notes
If preparing in advance: make the filling and sauce, place in individual ramekins, cover with cling film, and refrigerate. When ready to serve, add the cheese and broil for 10 to 12 minutes (until heated through).
💡 Chef's Tips
The key is cooking the scallops: a quick searing, then they finish gently in the oven. And for a perfectly smooth sauce: flour sprinkled over the vegetables, then gradually adding the stock to prevent lumps.
🔄 Variations
- Alcohol-free: replace the white wine with 5cl of lemon juice diluted with 10cl of fish stock, then reduce for 1 minute.
- For a more iodine flavor: add 1 tablespoon of shellfish concentrate (or a pinch of smoked paprika) to the sauce along with the cream.
