Cook macaroni in salted water according to package directions. Drain and set aside. In the meantime, melt the butter in a large saucepan and add the flour, making a roux. Cook for a minute or 2 to get the raw flour taste out. Add the milk and whisk together to insure no lumps. Bring to a boil and thicken the sauce. Add the cheese and stir until melted. Check for salt and pepper. Add the cooked macaroni and combine. Transfer to a buttered casserole or individual casserole dish. I add buttered bread crumbs and place under your broiler just to brown on the top.!! Serve immediately or can be frozen for later.