Heat oven to 450F. Pierce potatoes with fork; place on microwavable paper towel or roasting rack in microwave on high 6-8 minutes, turning once halfway through cooking, until almost tender.
Meanwhile, in large resealable food storage plastic bag, mix taco seasoning mix and cornmeal.
Cut cooked potatoes lengthwise into quarter; place in large shallow dish. Drizzle with oil; toss to coat. With large slotted spoon, place potatoes in plastic bag with seasoning mix; shake to coat. Arrange potatoes in single layer on ungreased cookie sheet.
Bake 8 minutes or until golden brown and tender. Serve with salsa if desired.