separated 1 Tablespoon Lemon Juice 1 Teaspoon Grated Lemon Peel Grated Parmesan Cheese Chop shrimp roughly and set aside. In the top of a double boiler over boiling water, melt butter. Add flour, mustard and tarragon. Cook, stirring constantly, for about 5 minutes, until mixture is thick. Add milk all at once and stir until a thick sauce is formed. Remove from heat and let cool slightly. Beat egg yolks, then beat then into the sauce. Add lemon juice and peel. Butter a 1-quart souffle dish and dust well with grated cheese. Start oven at 350 F. Beat egg whites until stiff but not dry. Stir shrimp into sauce, then fold in egg whites, as few strokes as possible. Do not overmix. Pour mixture into souffle dish and bake for about 35 minutes, until souffle is puffed, browned and fairly firm. Decorate with whole cooked shrimp, if desired. Serve at once. Serves 4 to 6.