{Gluten and Dairy Free} Grilled Chicken Pesto Pasta Salad

1 ½ pounds boneless, skinless chicken breasts (optional)
Salt and pepper, to taste
½ cup plus 3 tablespoons extra virgin olive oil, divided
12 ounces gluten-free pasta
2 ½ cups fresh basil leaves
2 cloves garlic
¾ teaspoon salt (the salt makes up for the lack of Parmesan cheese)
1 red bell pepper, cut in half and seeded
1 zucchini, cut in half
6 mushrooms
1 small red onion, thickly sliced
Daiya mozzarella cheese shreds (optional)

Preheat the oven to 400° F. If using, season the chicken with salt and pepper and drizzle with 3 tablesspoons olive oil. Cook the chicken in the oven or on the grill until cooked through to an internal temperature of 165° F, 15 to 20 minutes.Meanwhile, cook the pasta in a large pot of boiling water. Meanwhile, cook the pasta in a large pot of boiling water. Set the timer for a few minutes less than the package directions say and check the pasta. If it is still too firm, check it again in 30 seconds. Keep checking every 30 seconds until it is just right. Drain. Reserve 1 to 2 tablespoons of the starchy water from the boiled pasta when you drain it. This will help the pesto stick. While the pasta is boiling, blend the basil, garlic and ¾ teaspoon salt in the blender. Drizzle the ½ cup olive oil in as it blends. Grill the vegetables on a grill orin a grill pan until charred and cooked, but with some firmness left. You may also place them on foil on the top rack of an oven and broil.Add 2 to 3 tablespoons of the pesto to the noodles, depending on how strong you like it. I try some of the noodles to make sure it's the right amount. Add more as needed. It's easy to overdo it (see note). Add pasta water, if needed.Cut the veggies and chicken (if using) in roughly 1-inch cubes and toss with the pasta. Taste and season with salt and pepper, as needed. Sprinkle with mozzarella “cheese”.Note: You can freeze the rest of the pesto in ice cube trays for later. Transfer the frozen cubes of pesto to a freezer bag. It makes an easy dinner later and tastes great in scrambled eggs! You should have plenty left over.