This recipe came on a package of beautiful fresh haddock fillets that I bought today. So I tried it, and we really liked it.

BUBBLY FISH BAKE
2 lbs. fresh fish fillets
1 Tbs. fresh parsley, chopped
1 to 2 cloves garlic, minced
1 small onion, very thinly sliced
1 can condensed cream of mushroom soup, undiluted
1 c. sharp cheddar cheese, shredded

Preheat oven to 350 degrees F. Lightly grease a 9x12-inch casserole dish.
Lay fish fillets, in layers if necessary, skin-side-down in the dish. Season with parsley and garlic. Layer onion slices on the fish.
Spread soup evenly over fish and sprinkle with cheese. Bake 30 to 40 minutes, or until fish is flaky and onion is cooked. Serve with freshly ground pepper at the table.