In a large pan, heat the extra virgin olive oil over medium high heat. When the oil is hot, add the onion and garlic and sauté until the onion is translucent.
Add the penne, chicken broth and cherry tomatoes. Stir and bring the liquid to a boil, then cook for 10 minutes. Occasionally stir and make sure the noodles are covered with the liquid.
When the noodles are firm, but cooked, add the pesto. Stir to combine and heat for an additional minute.
Remove from heat and sprinkle the parmesan on top before serving.
Notes
Pasta will be cooked al dente. If you would like a less firm pasta, add an additional ½ cup of broth or water and cook for an additional 2 minutes.