In a large saucepan, bring 3 quarts of water to a boil.
Add the penne pasta and cook according to package directions. When draining, reserve ½ cup of the pasta water.
Put the sun-dried tomatoes in the reserved water to plump. (drain well when you are ready to add them to the mixture).
Toast the walnuts under the broiler until slightly browned. Be sure to watch closely as they can burn quickly.
Put the pressed garlic in a large bowl.
Add the walnuts, sun-dried tomatoes, olive oil, basil, salt, and cheeses. Add the pasta and toss all ingredients until pasta is well-coated.
Pour onto a platter and serve warm.
Serves 8 as a side dish; 6 as a main dish