Ingredients for Baked Fish With Onions
- 2 tablespoons olive oil
- 3 tablespoons butter
- 2 large yellow onions, thinly sliced
- 2 tablespoons all-purpose flour
- 1 1/2 cups whole milk
- Salt and pepper to taste
- 1/2 cup grated Swiss cheese
- 4 (6-ounce) cod fillets
- 1/2 cup fresh breadcrumbs
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How to Make Baked Fish With Onions
- Preheat oven to 400°F (200°C).
- Melt 2 tablespoons butter with 2 tablespoons olive oil in a large oven-safe skillet or casserole dish over medium heat. Add 2 large yellow onions, thinly sliced, and cook until softened and golden brown, about 15-20 minutes, stirring occasionally.
- Sprinkle 2 tablespoons all-purpose flour over the onions and cook for 2 minutes, stirring constantly.
- Gradually whisk in 1 ½ cups whole milk (or plant-based milk for dairy-free version), ensuring no lumps form. Bring to a simmer, then reduce heat and cook for 10-15 minutes, or until the sauce has thickened slightly. Season with salt and pepper to taste.
- If using cheese, stir in ½ cup grated Gruyere cheese (or your preferred cheese) into the onion sauce.
- Spread one-third of the onion sauce in the bottom of the prepared casserole dish.
- Arrange 4 (6-ounce) cod fillets evenly over the sauce.
- Sprinkle one-third of the remaining cheese (if using) over the cod.
- Pour the remaining onion sauce over the fish and top with the rest of the cheese (if using).
- Sprinkle 1/2 cup breadcrumbs evenly over the top. Dot with 1 tablespoon of butter, cut into small pieces.
- Bake for 20-25 minutes, or until the cod is cooked through and the topping is golden brown and bubbly.
Nutrition Information (Approximate per serving)
Sodium
19 g
Sugar
46g
Fat
94g
Carbs
16g
