Cook the pasta al dente, or to your preference. Drain, rinse, and set aside.
Meanwhile, while the pasta is cooking, heat the oil in a very large skillet over medium heat. Sauté the carrots, leek, and fennel for 7 to 10 minutes, until crisp-tender.
Add the pasta to the vegetables and mix well. Add the arugula and mix well. Remove from the heat.
Add about ½ cup of the pesto sauce to the pasta and mix thoroughly. Portion the pasta on serving dishes, sprinkle generously with the Parmesan, and serve immediately.