Melt butter in saucepan over medium heat. Add flour and cook 2-4 minutes, stirring constantly. Add milk and continue stirring. When mixture just begins to boil and thicken, immediately remove from heat. Stir in cheese. Add salt and pepper to taste. Serve immediately with warm Bavarian Pretzels.
To reheat, add a bit of cream and gently warm on the stovetop or in the microwave.