HEAT grill to medium-high heat.
SCOOP out seeds and flesh from centers of zucchini halves, leaving 1/4-inch-thick shells. Discard flesh and seeds. Grill zucchini 2 to 3 min. on each side or until tender.
COOK chorizo, peppers and onions in medium skillet on medium heat until done, stirring frequently. Add corn; cook and stir 2 min. or until heated through.
PLACE Singles pieces in zucchini shells; top with chorizo mixture.