Meatless Mexican Lasagna

2 cups frozen corn, thawed
1 can (15 ounces) black beans, rinsed and drained
1 can (14-1/2 ounces) diced tomatoes with basil, oregano and garlic undrained
1 can (4 ounces) chopped green chilies
3 green onions, sliced
2 teaspoons dried oregano
2 teaspoons dried cumin
4 corn tortillas (6 inches)
1-1/2 cups (6 ounces) shredded Mexican cheese blend
6 Tablespoons sour cream or plain yogurt

In a bowl, combine the first seven ingredients. Place two tortillas in an 11X17X2 inch baking dish coated with cooking spray. Spread with half of the corn mixture; sprinkle with half of the cheese. Repeat layers. Bake uncovered, at 400 degrees for 15-20 minutes or until heated through. Let stand for 5 minutes. Garnish each serving with a dollop of sour cream or yogurt.