In a 1½-quart casserole micro-cook ham, celery, 1 tablespoon water, covered, on 100% power for 3 to 4 minutes or until heated through.
Drain orange sections with pineapple, reserving ⅓ cup liquid.
In a 1-cup measure stir together cornstarch and cinnamon.
Stir into reserved liquid.
Micro-cook, uncovered, on 100% power for 1 to 1½ minutes or until thickened and bubbly, stirring every 30 seconds.
Drain liquid off ham and celery mixture.
Stir in thickened mixture. Stir in orange sections with pineapple.
Micro-cook, uncovered, on 100% power about 1½ minutes or until heated through.
Serve with hot cooked rice, if desired.