Baked Haddock With Creamy Lemon Mushroom Sauce
Frozen haddock fillets baked under a silky cream of mushroom sauce with fresh mushrooms, onions, and bright lemon juice, finished with a golden buttered breadcrumb topping. The sauce is aromatic with bay leaf, oregano, and paprika, creating a comforting one-dish meal. Serve for weeknight dinners or casual entertaining when you need something substantial but straightforward. This version uses canned soup as a base for speed while fresh mushrooms and lemon add brightness that the dish beyond typical casserole simplicity.
Ingredients
- 1 ½ lbs haddock fillets, frozencod1:1swapsadds fish
similar firm white fish
- 10 ½ oz cream of mushroom soup, cannedbechamel with fresh mushrooms0.5cup soup+0.25cup mushroom brothhomemade alternativedairy-free
more control, fresher taste
Full guide → - ½ cup milk, whole
- 1 ½ cups mushrooms, sliced
- 1 large onion, chopped
- 2 tbsp lemon juice, fresh
- 1 tsp paprika, ground
- ½ tsp salt, kosher
- ¼ tsp oregano, dried
- ¼ tsp black pepper, ground
- 1 whole bay leaf, dried
- 1 cup bread crumbs, buttered
- ½ tsp poultry seasoning, dried
- butter, for dotting and greasing
Instructions
- 1
Place frozen fillets in a shallow buttered baking dish.
- 2
Combine cream of mushroom soup, milk, sliced mushrooms, chopped onion, lemon juice, paprika, salt, oregano, pepper, and bay leaf in a saucepan.
- 3
Simmer sauce 10 minutes, then pour over fillets.
- 4
Toss buttered breadcrumbs with poultry seasoning, then distribute evenly over sauce.
- 5
Dot top with additional butter.
- 6
Bake until fish flakes easily, approximately 45 minutes.
Tips
Thaw fillets partially in refrigerator before baking to ensure even cooking throughout, reducing risk of dry edges.
Use fresh lemon juice rather than bottled for brighter flavor; add zest to breadcrumb topping for additional citrus note.
Substitute cream of mushroom soup with homemade bechamel mixed with sauteed mushrooms if preferred.
Good to Know
Refrigerate covered up to 3 days. Not ideal for freezing due to breadcrumb texture degradation and sauce separation.
Prepare sauce, assemble in dish, cover, and refrigerate up to 24 hours before baking. Add 5-10 minutes to bake time if baking cold.
Serve directly from baking dish with crusty bread, steamed vegetables, or rice pilaf. Pairs well with white wine.
Common Mistakes
Use thawed or partially thawed fillets to avoid dry outer edges and undercooked centers
Don't skip the 10-minute sauce simmer to ensure flavors meld and onions soften
Distribute breadcrumbs evenly to prevent burnt and raw spots in topping
Substitutions
Dairy-Free Swaps
more control, fresher taste
Full guide →General Alternatives
FAQ
Can I use fresh instead of frozen haddock?
Yes, use fresh fillets of same weight. Reduce baking time to 25-30 minutes since they cook faster. Check for doneness at 20 minutes by testing flake resistance.
What if I don't have poultry seasoning?
Mix 0.25 teaspoon each dried thyme, sage, and marjoram, plus pinch of nutmeg. Alternatively, use Italian seasoning or Cajun seasoning for different flavor profile.
Can I make this ahead and freeze?
Freeze unbaked dish up to 1 month. Thaw overnight in refrigerator, then bake as directed, adding 10 minutes. Freezing cooked casserole causes breadcrumb sogginess.