Step 1Grease 6-cup souffle dish and sprinkle with about 1 tablespoon Swiss cheese. Finely grind 2 teaspoons chopped almonds and dust bottom and sides of souffle dish.
Step 2Melt 1 tablespoon butter in saucepan over medium heat. Saute shallot 1 minute. Stir in spinach and 1/4 teaspoon salt. Cook 5 minutes, then transfer mixture to plate. Set aside.
Step 3Melt 3 tablespoons butter in same saucepan. Stir in flour until well blended. Remove from heat. Add boiling milk and beat with wire whisk until smooth. Beat in 1/2 teaspoon salt, black pepper, dash cayenne pepper and dash nutmeg. Return to heat and cook over medium-low heat until very thick, about 1 minute, stirring constantly. Remove from heat.
Step 4Add egg yolks, 1 at a time, to hot mixture, beating until smooth. Stir in spinach and remaining almonds. Adjust seasoning.
Step 5Beat egg whites with dash salt until soft peaks form. Fold 1/4 egg whites into sauce. Stir in all but 1 tablespoon remaining grated cheese. Gently fold in remaining egg whites. Pour into prepared souffle dish. Sprinkle with remaining cheese and bake at 375 degrees until golden brown and puffed, 30 minutes.