While the dough is rising, start on the béchamel sauce. Whisk the butter and flour in a small sauce pan over medium heat.

When it begins to brown and bubble, add ¼ cup milk. Whisk until smooth. Add the blue cheese and black pepper. When well-mixed, add additional milk until it reaches a thick, but spreadable consistency. You want the sauce to stay in place on the crust, but be easily spread. Turn off heat and leave it on the stove.