Basic Savoury Soufflé

• 2 tablespoons butter
• 2 tablespoons flour
• ½ pint

Melt butter; add flour gradually and mix to a smooth paste, stirring constantly. Add hot milk and cook in double saucepan until sauce is smooth and thick. Remove from fire and add egg yolks, one by one, alternately with a mixture of grated Gruyère and grated Parmesan. Mix well and return to fire. Cook until cheese melts. Add generous amounts of salt and pepper, remove from fire and allow to coo