Preheat grill.
Whisk olive oil, vinegar, dill, salt and pepper together in a small bowl; set aside.
Assemble skewers, starting with garlic, mushroom, zucchini, onion, and tomato. Repeat until skewer is full, leaving 1 inch at each end of skewer. Brush each skewer with olive oil marinade. Grill for about 6 minutes, or until vegetables are cooked to your liking, turning skewers once after 3 minutes.