Preheat grill to medium heat, about 350 to 450 degrees.
If using marinade, whisk ingredients together (olive oil, lemon juice and zest, rosemary, and garlic). Season to taste with salt and pepper. Set aside.
Brush both sides of vegetables with olive oil, then sprinkle lightly with salt and pepper. Skewer tomatoes or place in a grill basket. Place veggies on grill and close lid.
Cook vegetables until brown grill marks appear, then flip. (If using a grill basket, shake occasionally, cooking until tomatoes are tender.)
Continue cooking vegetables until there are grill marks on their other side and they are tender. (If veggies char before becoming tender, move them to a cooler part of the grill to finish cooking through.)
Remove veggies from grill. Season to taste with additional salt, if needed. Drizzle with marinade, if using.
Serve vegetables immediately or at room temperature. Enjoy!
Calories are an estimate and do not include marinade.