Melt the butter in a large pot over medium heat. Add the grated garlic. Cook for 2-3 minutes until the garlic starts to turn golden. Stir often.
Pour in the low sodium chicken broth and half & half. Season to taste with salt and pepper. Bring to a boil.
Once boiling, add the rigatoni. Cook until the pasta is al dente, about 15 minutes. Stir often so the pasta doesn’t stick together. Most of the liquid will be absorbed but there should still be some left in order to form the sauce. Add additional water or broth as needed.
Once the pasta is cooked, add the juice and zest of 1 lemon. Season to taste with salt and pepper. Stir to combine. Add the freshly grated parmesan cheese. Stir until well combined and melted.
Serve immediately. Divide among bowls and top with additional lemon juice, lemon zest, parmesan cheese, and fresh parsley as desired.