Preheat oven to 425*F.
In a small bowl, combine balsamic vinegar, olive oil, garlic powder, onion powder, salt, and pepper. Stir to combine.
6 tablespoon Balsamic Vinegar, ¼ Cup Extra Virgin Olive Oil, 2 teaspoon Garlic Powder, 2 teaspoon Onion Powder, 1 ¾ teaspoon Kosher Salt, Black Pepper to Taste
Arrange the sliced eggplant, zucchini, bell pepper, and onion on two baking sheets. This allows the vegetable to have space to roast. Then, brush the vegetables liberally on both sides with the balsamic mixture. You may have a little leftover depending on the size of your vegetables. Just discard it.
1 Small Italian Eggplant, cut into ½" rounds, 1 Medium Zucchini, cut into ¼" planks, 1 Medium Red Bell Pepper, seeded and quartered, 1 Medium Red Onion, cut into ½" rounds
Roast the vegetables in a 425*F oven on the middle and top racks for 33-37 minutes, stopping to flip the vegetables over with a spatula after 20 mintues.
Place the ciabatta rolls into the oven during the last few minutes to warm up.
4 Ciabatta Rolls