Bring large pot of salted water to a boil. Cook desired pasta to al dente and drain. Set aside. While pasta is cooking, grate your parmesan cheese.
In a large skillet with high sides, melt your butter and then stir in the flour to create a paste. Cook 30 seconds.
Slowly add the milk into the roux, whisking as you go, until its completely incorporated. Add the minced garlic. After 2-3 minutes of whisking, sauce should simmer slightly and thicken. Pour in the fat free half and half and salt. Whisk again for another minute to warm it through.
Once your white sauce has thickened nicely, slowly incorporate the grated parmigiano reggiano cheese in, about 1/4 cup at a time, until its melted smoothly into the sauce. After the cheese has been completely melted in, taste and adjust your seasonings. This sauce has a tendency to seem sweet because of all that dairy and garlic, so don't be afraid to add extra salt because it most likely will need it.