Step 1

Bring a large pot of water to a boil over medium-high heat. Add penne pasta and a little bit salt, and cook till al dente (fully cooked but still firm) about 8-10 minutes, or according to package directions. Do not overcook the pasta. Turn off the heat and reserve at least 1/4 cup of pasta water, then drain the pasta in a colander and let it cool for 1 minute.

Step 2

Transfer pasta into a large mixing bowl and add pesto and reserved pasta water (1/4 cup or more, if desired). Season with salt and pepper and toss well to coat. Stir in cherry tomatoes and parmesan cheese.

Step 3

Serve immediately. Sprinkle extra parmesan on top, if desired.