Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain and reserve.
In a microwave-safe bowl, combine milk, flour and salt and pepper to taste; whisk or beat until smooth. Add butter and cheese; microwave on high for 5 minutes and whisk until smooth. Microwave for an additional 4 to 5 minutes and whisk or beat until smooth and no lumps remain.