Preheat oven to 400 degrees F. Place vegetables on a large baking sheet and drizzle with olive oil and balsamic vinegar. Season with salt and pepper and toss well. Roast for 20 minutes, stirring occasionally.
Heat pitas and either slice them open and stuff them with lettuce, roasted veggies, feta cheese, and tzatziki or place everything on top of the pita and eat!