Heat oven to 400 degrees.

Cut the stem end off the eggplant and then cut it in half lenghtwise. Cut each half into 4 or 5 strips and then into 2" sections. Place the eggplant in a large mixing bowl.

Cut the bell pepper into 2" pieces. Add to the bowl with the eggplant.

Peel the onion, cut it in half and then into 1/2" wedges. Add onion to the bowl.

Peel the garlic cloves and slice them in half if large. Add the garlic to the bowl.

Add the mushrooms whole to the bowl. If they are very large, cut them in half.

Toss all the vegetables in the bowl with the olive oil. Do not add the tomatoes or pesto.

Put the vegetables in a 9"x14" baking dish and put it in the oven for about 20 minutes.

After 20 minutes, add the tomatoes and the pesto to the pan and stir to combine. Cook for another 10-15 minutes until the tomatoes are soft and all the other vegetables are tender and browned.

Remove from the oven and season with salt and pepper.