Heat large pot of water to boil, toss in a pinch of salt. Add fettccine to boiling water; cook until al dente.

Meanwhile, melt butter in skillet of medium heat, stir in flour until smooth and fully incorporated. Slowly whisk in milk. Cook, stirring often until sauce thickens, about 5 minutes. Remove from heat. Stir in 1/4 cup of the cheese. Add salt and pepper to taste. Toss sauce with drained pasta. Toss in the remaining cheese.