Blend the basil, spinach, garlic, salt and pepper in the food processor with a bit of oil, just enough to bring the ingredients together. Pulse in the parmesan cheese and adjust seasoning.
Toss the veggies with half of the pesto and pour onto a sheet tray. Roast veggies until tender, about 12 minutes. Let cool and set aside.
Mix the remaining pesto with balsamic vinegar for the dressing for the salad. Toss salad with veggies and top with dressing.