In a small saucepan, melt butter and stir in flour until smooth.
Gradually add milk and cook, stirring constantly, and bring to a boil.
Reduce heat to simmer for 2 minutes while stirring frequently.
Remove from heat and stir in cheese until melted.
Add black pepper and set aside.
In a large bowl, whisk egg yolks and gradually add cheese mixture. Whisk until smooth. Set aside.
Preheat oven to 325° F.
Lightly butter a 6-cup soufflé dish and dust with flour.
In a separate bowl, whip egg whites until stiff peaks form.
Gently fold egg whites into yolk mixture, ⅓ of beaten whites at a time.
Pour egg mixture into dish; it will be ½ to ⅔ full.
Bake 45 minutes until puffy and golden.
Serve immediately.
