Step 1Bring a large saucepan of water to boil.
Step 2Meanwhile, heat the olive oil in a medium sized stockpot. Add the zucchini, squash and onion and cook until soft, about 5 minutes. Add the chicken broth, tomato paste, cooked chicken and diced tomatoes. Bring the soup to a boil, then reduce the heat to low, add the pesto and simmer for 10 minutes.
Step 3When the pasta water is boiling, add salt, then the noodles. Cook according to package directions until tender, about 5 to 7 minutes. Divide the noodles among soup bowls, then ladle the hot soup over the top.