If you have the time, you may achieve the ultimate in juicy succulence for a salmon fillet by slow-baking. This produces the same moistness, with greater uniformity, than the celebrated fish poacher. 

Baking time is difficult to predict, as it depends on the size of the fillet and also the exact temperature of the oven. A small change in oven temperature here can have a marked effect on the time. On the other hand, the baking may be done well ahead of time. The fish will remain moist indefinitely, including overnight in the refrigerator. 

For a small fillet, allow perhaps half an hour. A large fillet may take an hour or more. (If is seems that the fish is taking too long, turn up the heat somewhat; this may produce a slight crust, but the center will remain moist.)

Baking will take place at 275 or 250 degrees F. There is no need to preheat oven. 

Bake uncovered until done, about 125 degrees on the little dial thermometer (see Basics). 

Variations
     Any of the coatings in the Baked Fillets section may be considered. 
     Thin lemon slices, sprinkled with brown sugar, work very well here. Use these with or without a bed of spinach under the salmon. 

The salmon here is baked in a generous quantity of flavored milk. (For a somewhat similar treatment, using little milk or cream, see the section on Baked Fillets). 

Serves 3

Preheat oven to 325 degrees F.

Place salmon in unoiled baking dish. Add milk to depth of ¼ inch or slightly more. Enrich with some cream, if desired.
To the milk add the bay leaf, clove, onion, and thyme.
Sprinkle the top of the salmon with dill.
Bake the fish until tender, 30 to 45 minutes, 130 degrees F. on the instant dial thermometer. Baste from time to time.

Variations

Instead of dill, use raw sliced mushrooms. Sprinkle with very little thyme, and baste frequently.

In the milk add pieces of cucumber, peeled and seeded. (Preferably steep cucumber pieces a minute or two in a little salt and very little sugar.)

If a fillet has its skin, leave it on and bake skin-side up. Peel off skin just before serving. Baste and sprinkle top of salmon with dill.

This is a novelty, invented by a river guide in Oregon. As if salmon weren’t rich enough, this recipe adds brown sugar, onions, and mayonnaise. The result is delicious, though not popular with nutritionists.

(Adapted from Junior Service League of Jackson County, Rogue River Rendezvous.)

Serves 4

Preheat oven to 350 degrees.

Place fillet skin side down in the unoiled baking dish. Poke the salmon with a fork several places and distribute lemon juice over the surface. Let stand 15 minutes.

Cover the salmon with a thin layer of brown sugar. Follow with a layer of thinly sliced onions, [.. cooked 1 or 2 minutes in water?.. ] then a thin layer of mayonnaise.

Bake uncovered until salmon is done, 130 degrees F. on the instant dial thermometer. Top should be light golden in color.

Variations
The original had a ¼ inch layer of brown sugar, with mayonnaise 1/8 to ¼ inch thick.