PIERCE squash several times with fork or sharp knife to allow steam to escape. Microwave on HIGH 10 min. or just until squash is softened, turning after 5 min. Let stand 5 min.

CUT squash in half; remove and discard seeds. Use fork to scrape insides of squash to form strands; place in large bowl. Add remaining ingredients; toss lightly with fork. Spoon into 1 squash shell; discard remaining shell.

MICROWAVE 2 min. or until heated through.