Cut chicken sausage into 1/2" rounds
Cook pasta according to package directions
While pasta is cooking, heat sausage in a deep skillet until heated through, about 6-8 minutes
Drain pasta, saving about 1/2 cup of pasta water
Add drained pasta to skillet with sausage, turn heat to very low
Add jarred pesto to taste and mix. Add pasta water if needed to get to the desired consistency.
Top with fresh ground pepper and fresh grated parmesan