Grilled Vegetables with Tomato Oil

Cut onions crosswise in 3/4-inch-thick slices. Run a slender skewer across and through center of each slice to hold rounds flat and secure; put as many slices on skewer as will fit.

Rinse eggplant, discard stem, and cut crosswise into 3/4-inch-thick rounds. Thread skewers across and through rounds as directed for onions.

Rinse zucchini, trim ends, and cut crosswise into 3/4-inch-thick rounds. Thread on skewers as directed for onions.

Rinse peppers, cut into quarters lengthwise, stem, and seed. Thread thin skewers through center of slices, leaving about 1/4 inch between pieces.

Rinse mushrooms, trim stems flush with caps, and save stems for other uses.

Mix olive oil and tomatoes.

Brush mixture onto vegetables.

Set vegetables on a barbecue grill over a solid bed of hot coals or high heat on a gas grill (you can hold your hand at grill level only 2 to 3 seconds). Close lid on gas grill. Cook, turning as needed, until vegetables are browned and tender when pierced, 8 to 10 minutes.

Transfer to a platter as cooked.

Slice mushrooms.

Remove vegetables from skewers.

Add mushrooms to platter and season vegetables to taste with salt and pepper.

Serve hot or at room temperature.