Another simple winner from the old world is the English butter and cream style horseradish baste.
Lay fillet flat side down in a baking dish or foil greased with a little butter. Melt a stick of butter and blend in Beaver cream style horseradish (especially for prime rib, blue label, white lid) until it has the consistency of hollandaise. Chop fresh dill weed into the mixture to taste. Baste with mixture and bake in 400 degree oven for about 10 minutes, then pop to broil to brown the glaze.
Save some of the mixture for a garnish sauce and enjoy. Also excellent with spring chinook, fresh coho, etc.
Serve with asparagus and pilaf, sauteed oyster mushrooms are a nice touch as well.
Fish fillet quality varies widely with condition of fish and freshness. A fresh mint-bright May summer run buck will melt in your mouth as will a fresh Willamette or Copper springer. Coho caught in the saltchuck and grilled the same night will amaze you. Fresh sockeye is perhaps the best of the bunch, definitely for smoking in a mixture of apple and alder chips.