Preparation Preheat oven to 375°F. and butter and flour a 2-quart soufflé dish, knocking out excess flour. In a large saucepan cook onions in butter over moderate heat, stirring, until softened. Add salmon and cook, stirring, 5 minutes. Stir in flour and cook over moderately low heat, stirring, about 2 minutes. In a small saucepan heat milk to a bare simmer and add gradually to salmon mixture, stirring constantly. Boil salmon mixture, stirring constantly, until thickened, about 2 minutes. Remove pan from heat and whisk in egg yolks, dill, and Parmesan. Transfer salmon mixture to a large bowl. In another large bowl with an electric mixer beat egg whites with a pinch salt until they just hold stiff peaks. Stir one fourth whites into salmon mixture to lighten and fold in remaining whites gently but thoroughly. Pour mixture into prepared dish and put in middle of oven. Reduce oven temperature to 350°F. and bake soufflé 50 minutes, or until puffed and golden and a tester comes out clean. Serve immediately.
Preparation Preheat oven to 375°F. and butter and flour a 2-quart soufflé dish, knocking out excess flour. In a large saucepan cook onions in butter over moderate heat, stirring, until softened. Add salmon and cook, stirring, 5 minutes. Stir in flour and cook over moderately low heat, stirring, about 2 minutes. In a small saucepan heat milk to a bare simmer and add gradually to salmon mixture, stirring constantly. Boil salmon mixture, stirring constantly, until thickened, about 2 minutes. Remove pan from heat and whisk in egg yolks, dill, and Parmesan. Transfer salmon mixture to a large bowl. In another large bowl with an electric mixer beat egg whites with a pinch salt until they just hold stiff peaks. Stir one fourth whites into salmon mixture to lighten and fold in remaining whites gently but thoroughly. Pour mixture into prepared dish and put in middle of oven. Reduce oven temperature to 350°F. and bake soufflé 50 minutes, or until puffed and golden and a tester comes out clean. Serve immediately.