Mince the garlic and dice the onion. Heat a cast iron pan over medium high heat, adding the olive oil. Add the garlic and onion and sauté until the onion has softened and the garlic is fragrant. Add the passata and stir until the mixed consistently and the passata is heated through.
Remove from the heat and sprinkle the basil overtop, reserving 1 Tbsp of basil for topping at the end. Arrange the vegetables on the sauce, alternating between the different vegetables (photo above was eggplant, tomato, yellow zucchini, green zucchini). Drizzle with pesto. Cover the pan wither either an oven-ready lid, or with tin foil. Place in the oven and bake for 40 minutes, then remove foil and bake for another 10-20 minutes, until vegetables have reached desired level of doneness.
Remove from the oven, top with olive oil, cheese and basil, then serve.