Ingredients
For the Fish:
- 1 lb (450 g) frozen white fish fillets (pollack, coley, or hake), defrosted, skinless and boneless
- Salt, to taste
- Freshly ground black pepper
For the Mornay Sauce:
- 2 tablespoons butter (unsalted or salted)
- 2 tablespoons all-purpose flour
- 1 1/2 cups milk (semi-skimmed or reconstituted from powder)
- 1 cup medium or mature cheddar cheese, grated
- Salt and pepper, to taste
Optional Sides:
- Mashed potatoes
- Steamed or boiled peas
- Roasted or steamed vegetables
Equipment
- 4 individual gratin dishes or 1 larger ovenproof dish
- Medium saucepan
- Balloon whisk or sturdy whisk
- Sharp knife and chopping board
- Kitchen paper for drying fish
- Cheese grater
- Oven tray (optional, to catch any spills)
Step 1: Prepare the Fish
- Defrost the fish fully. Pat each fillet dry using kitchen paper—this removes excess moisture and helps the sauce adhere to the fish.
- Cut the fish into bite-sized pieces, roughly uniform so they cook evenly.
- Season lightly with salt and pepper, adjusting depending on whether your cheese or butter is salted.
Tip: Cutting fish into smaller pieces ensures every bite is coated with the creamy sauce and gives a more elegant presentation.
Step 2: Make the Mornay Sauce
- In a medium saucepan, melt the butter over medium heat.
- Once melted and foaming, sprinkle in the flour. Use a balloon whisk to combine thoroughly. This mixture is called a roux, which will thicken the sauce and give it a smooth, velvety texture.
- Whisk constantly as the butter and flour cook for 1–2 minutes. This helps eliminate any raw flour taste and prevents lumps.
- Gradually pour in the milk, adding it in a slow stream while whisking continuously. This ensures the sauce is smooth and lump-free.
- Continue whisking and bring the mixture to a gentle simmer. The sauce will begin to thicken as it heats.
- Once the sauce is thickened and smooth, reduce the heat slightly and stir in the grated cheese.
- Season with salt and pepper to taste. The sauce should be glossy, rich, and able to coat the back of a spoon.
Tip: If the sauce is too thick, whisk in a little extra milk until you reach the desired consistency.
Step 3: Assemble the Dish
- Preheat the oven to 375°F (190°C).
- Lightly grease your ovenproof dish or individual gratin dishes.
- Arrange the fish pieces evenly in the dish.
- Pour the hot Mornay sauce over the fish, making sure all pieces are coated.
Tip: For extra flavor and texture, sprinkle a little extra grated cheese over the top before baking.
Step 4: Bake
- Place the dish(es) on an oven tray to catch any spills.
- Bake in the preheated oven for 20–25 minutes, or until the fish flakes easily with a fork and the sauce is bubbling lightly.
- For a golden, gratin-style topping, you can broil for the last 2–3 minutes.
Step 5: Serve
- Serve immediately with mashed potatoes and steamed peas, or your choice of simple vegetables.
- The creamy sauce can also be spooned over rice or pasta for a different variation.
Serving Suggestion: A sprinkle of fresh chopped parsley adds color and freshness.
Tips and Variations
- Vegetable Boost: Stir in small pieces of cooked broccoli, cauliflower, or spinach into the sauce before baking.
- Cheese Options: Swap cheddar for Gruyère or a mild Swiss cheese for a slightly nutty flavor.
- Make Ahead: The sauce can be prepared in advance and stored in the fridge. Reheat gently before assembling with fish.
- Budget Tip: Frozen white fish is cheaper but still delivers great flavor. Fresh cod or haddock works if preferred.
Storage
- Leftovers: Store in an airtight container in the fridge for up to 2 days. Reheat gently in the oven or microwave.
- Freezing: Not recommended for best texture, as the fish can become watery when frozen and reheated.
Nutrition (approximate per serving, 1/4 recipe)
- Calories: 350–400 kcal
- Protein: 28 g
- Fat: 15 g
- Carbohydrates: 15 g
- Fiber: 2 g
- Calcium: 150 mg
