Preheat the oven to 350 degrees.
Melt butter in a saucepan. Add shallots and wine. Reduce over medium heat until wine is almost evaporated. Stir in the flour and cook over medium heat for 5 minutes. Pour the milk in the roux. Whisk and heat until the sauce thickens and comes to a boil. Season with pepper and nutmeg.
Mix in the chopped salmon and the mushrooms sauteed in butter. Stir in the egg yolks. In the bowl of a mixer, combine the egg whites with cream of tartar and whip the egg white mix until medium firm. Fold into the salmon mixture. Butter and flour a 7 inch (17.5 cm) round souffle mold.
Spoon the souffle mix into mold.
Bake 30 minutes at 350 F.(180 C). Serve immediately.
