Fish Gratin with Button Mushrooms

Indulge in the comforting flavors of Fish Gratin with Button Mushrooms, a crowd-pleasing seafood casserole that combines tender white fish fillets, earthy mushrooms, and a velvety cream sauce. Topped with a golden, cheesy breadcrumb crust made with Parmesan and Gruyère, this dish is irresistibly rich and satisfying. The addition of lemon juice and garlic adds a zesty brightness, while fresh parsley brings a touch of freshness to each bite. Perfect for family dinners or special occasions, this oven-baked gratin takes only 20 minutes of prep and is ready to serve in just under an hour. Pair it with steamed vegetables or crusty bread for a complete meal that’s sure to impress.

Nutriscore Rating: 62/100

Prep Time:20 mins

Cook Time:30 mins

Total Time:50 mins

Servings: 4

Ingredients

• 500 g white fish fillets (e.g., cod, haddock)
• 200 g button mushrooms, sliced
• 30 g unsalted butter
• 25 g all-purpose flour
• 350 ml milk
• 100 ml heavy cream
• 50 g grated Parmesan cheese
• 100 g grated Gruyère or Cheddar cheese
• 1 tbsp lemon juice
• 2 cloves garlic, minced
• 2 tbsp Italian parsley, chopped
• 1 tsp salt
• 0.5 tsp black pepper
• 50 g breadcrumbs
• 1 tbsp olive oil

Directions

Step 1

Preheat the oven to 200°C (400°F). Lightly grease a large baking dish with olive oil or butter.

Step 2

Season the white fish fillets with half the salt, pepper, and lemon juice, then set aside.

Step 3

Heat the butter in a large pan over medium heat until melted. Add the minced garlic and cook for 1 minute until fragrant. Add the sliced button mushrooms and cook for about 5 minutes until softened and lightly browned.

Step 4

Sprinkle the flour over the mushrooms in the pan and stir well to coat. Slowly pour in the milk, whisking constantly, to form a smooth sauce.

Step 5

Add the heavy cream, Parmesan cheese, and half of the Gruyère (or Cheddar) cheese to the sauce. Stir until the cheeses melt and the sauce thickens slightly. Season with the remaining salt, black pepper, and chopped parsley.

Step 6

Place the seasoned fish fillets in the prepared baking dish. Pour the creamy mushroom sauce evenly over the fish.

Step 7

In a small bowl, combine the breadcrumbs, the remaining Gruyère (or Cheddar) cheese, and olive oil. Mix well, then sprinkle the crumb mixture evenly over the dish.

Step 8

Bake the gratin in the preheated oven for 25-30 minutes, or until the topping is golden brown and the fish is cooked through (it should flake easily with a fork).

Step 9

Remove the gratin from the oven and let it rest for 5 minutes before serving. Garnish with additional parsley, if desired, and serve warm with a side of steamed vegetables or crusty bread.

Nutrition Facts

Serving size	(1465.3g)

Amount per serving	% Daily Value*
Calories	2216.2

Total Fat 135.0g	0%
Saturated Fat 74.2g	0%
Polyunsaturated Fat 1.6g
Cholesterol 606.1mg	0%
Sodium 5152.0mg	0%
Total Carbohydrate 88.0g	0%
Dietary Fiber 6.0g	0%
Total Sugars 26.1g
Protein 164.1g	0%

Vitamin D 1200.3IU	0%
Calcium 1844.3mg	0%
Iron 7.2mg	0%
Potassium 2925.5mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 54.6%

Protein: 29.5%

Carbs: 15.8%