Preheat the oven to 400 degrees F.
Butter the inside of an 8-cup souffle dish and sprinkle evenly with Parmesan.
Melt the butter in a small saucepan over low heat.
Stir in flour and cook, stirring constantly, for 2 minutes.
Remove heat and whisk in the milk, 1/2 teaspoon salt, 1/4 teaspoon black pepper.
Cook over low heat, whisking constantly, for 1 minute, until smooth and thick.
Remove heat again and whisk in the egg yolks, one at a time.
Stir in the Roquefort and the 1/4 cup of Parmesan.
Pour in a mixing bowl.
Put the egg whites, cream of tartar, and a pinch of salt in a mixer bowl.
Whisk on low speed for 1 minute, on medium speed for 1 minute, then finally on high speed until they form firm, glossy peaks.
Whisk 1/4 of the egg whites into the cheese sauce and fold in the rest.
Pour into the souffle dish and smooth the top.
Use a spatula to trace a circle into the souffle.
Lower oven temp to 375 degrees F.
Bake for 30 to 35 minutes until puffed and brown.
Do not open oven while it is baking!
Serve immediately.