Heat oven to 450°F. Pierce potatoes with fork; place on microwave-safe paper towel or roasting rack in microwave. Microwave on HIGH for 6 to 8 minutes or until almost tender, turning once halfway through cooking.
Meanwhile, in resealable food storage plastic bag, combine taco seasoning mix and cornmeal; mix well.
Cut cooked potatoes lengthwise into quarters; place in large shallow dish. Drizzle with oil; toss to coat. With large slotted spoon, place potatoes in plastic bag with seasoning mixture; shake to coat. Arrange potatoes on ungreased cookie sheet.
Bake for 8 minutes or until golden brown and tender.