This ratatouille dish is perfect for your bounty from the garden or farmers' market. To keep the veggies from burning, watch them carefully while grilling. If necessary, move any that are cooking too quickly to a cooler spot on the grill.
Combine eggplant, squash, zucchini, bell pepper, and onion in a 9x13-inch baking dish. Whisk oil, vinegar, garlic, 1 tsp. basil, 1 tsp. oregano, 1 tsp. thyme, 1/2 tsp. pepper, and 1/4 tsp. salt in a small bowl; pour the marinade over the vegetables. Toss the vegetables until well coated. Let stand at room temperature for 2 hours, tossing the vegetables in the marinade occasionally.
Preheat grill to medium-high.
Remove the vegetables from the marinade (reserve the marinade). Grill the vegetables until tender and grill marks appear, basting with the marinade and flipping halfway through; 6 to 10 minutes for eggplant, squash, and zucchini; 8 to 10 minutes for onion; and about 10 minutes for bell pepper.
Coarsely chop the grilled vegetables. Transfer to a large bowl and add tomatoes and the remaining 1/2 tsp. each pepper and salt, and 2 tsp. each basil, oregano, and thyme. Toss well to combine.
Equipment: Charcoal or gas grill
Tip: To keep the onion rings intact, cut the onion into even slices and hold the rings closest to the center with tongs or a long spatula when flipping them.