Bring a large pot of water to a boil. Add pasta; cook according to the package directions. Just before the pasta is done add broccoli florets and continue cooking with pasta until done. (We like our broccoli with a little crunch to it.) Drain pasta and broccoli; set aside.
In the same pot, melt butter over medium heat. Stir in garlic; cook 30-60 seconds. Whisk in flour; cook 1-2 minutes or until a thick paste forms, stirring constantly.
Add chicken broth, salt, onion powder, paprika and pepper. Slowly whisk in warmed half-and-half cream and bring to a low simmer. Cook until the sauce has thickened, stirring frequently. Remove from the heat. Stir in cheeses until melted.