Peel eggplant and cut into cubes. Salt and place into strainer and drain. This removes some of the bitterness you can have with eggplant. Peel and slice onions. Cut zucchini and yellow squash on the diagonal in slices.
Peel carrots, cut into slices on the diagonal. Blanch 4 minutes in boiling water. Cut cherry tomatoes in half. I use a stovetop grill for this dish. It is easier to do each vegetable separately and then combine.
Coat vegetable with a very light coating of vegetable oil. A vegetable spray will work. Cook each vegetable until done. They will only take a few minutes each. Salt and pepper to taste as you are cooking. You can also sprinkle fresh herbs on the vegetables before cooking.
Gently toss vegetables together. Drizzle with olive oil. Season with salt and pepper to taste.