Toss your sliced peppers, zucchini and onions with the olive oil, salt u0026 pepper and layer them on a large baking sheet.
Roast them in the oven for 25-30 minutes, tossing halfway through.
While the veggies roast, prepare your pasta as instructed on package. Drain and set aside.
For the walnut pesto, add in all of the pesto ingredients to a food processor and blend for 3-4 minutes until smooth. Scrape down the sides of your food processor as needed.
Once the pesto is ready, stir it into the pasta with the roasted veggies and the fresh mozzarella. Serve fresh warm or cold!
Leftovers will stay fresh in the fridge for up to 1 week. The pesto can be made in advance and refrigerated for up to 1 week.