Preheat the oven to 400 degrees (F). Spray a rimmed baking sheet with cooking spray. Place chicken, arugula, bread crumbs, Parmesan cheese, pesto, onion, 4 cloves of minced garlic, eggs and salt and pepper in a large mixing bowl. Using your hands (preferred) or a spoon, gently mix everything together until evenly incorporated. Shape the mixture into golf ball-sized meatballs and place on prepared cooking sheet. Bake meatballs for about 18-22 minutes, flipping half way through to ensure even browning, until they are completely cooked though and no longer pink in the middle.

Meanwhile layer a large platter with arugula. Prepare the spaghetti and zoodles and arrange decoratively around the edge of the platter. Arrange the cooked meatballs down the center of the platter and top with tomatoes, basil and mozzarella. Drizzle everything with the garlic oil and sprinkle with additional Parmesan cheese, flaky salt and chili flakes and serve immediately.