Preheat the oven to low broil

Cut the peppers, onion, zucchini, and squash into large chunks

Put the mushrooms, peppers, onion, zucchini, and squashinto a 1 gallon zippered storage bag

Add the Italian dressing to the storage bag

Close the bag

Carefully knead the contents of the bad so that the vegetables are completely coated with the sauce

Refrigerate the vegetables for at least 30 minutes (the longer the better)

Spray the broiler pan with cooking spray

Arrange the vegetables on the broiler pan so that they aren’t touching (or touching as little as possible)

Put the broiler pan in the oven and broil the vegetable les for 10 minutes

Turn the pieces over

Broil for another 10 minutes

Serve