Bring a medium pot of salted water to a rolling boil. Add the pasta and cook until al dente, following package instructions. Drain the pasta in a strainer and set aside.
In a saucepan, melt the butter over medium heat. Once melted, whisk in the flour and cook for about 1 minute until the mixture appears slightly thickened and bubbly, with a light golden color.
Gradually pour in the milk while whisking continuously to avoid lumps. Continue whisking until the mixture thickens, about 2-3 minutes, and starts to coat the back of a spoon.
Add the shredded cheese to the sauce in small handfuls, stirring until melted and smooth. Season with salt and pepper to taste. The cheese sauce should turn creamy and velvety.
Combine the cooked pasta with the cheese sauce, stirring gently until all pieces are evenly coated and the sauce is thickened further. The mixture should be hot and creamy with a glossy appearance.
Serve immediately while hot, optionally garnished with extra cheese or herbs for presentation.
