PREPARATION:
- Preheat oven to 350°F. Spray 13X9-inch baking dish with nonstick cooking spray.
- Heat oil in large skillet over medium-high heat until hot. Add onion; cook and stir 3 minutes or until tender. Add beans, tomatoes with juice, corn and taco seasoning mix. Bring to a boil over high heat. Reduce heat to low and simmer 5 minutes.
- Place 2 tortillas side by side in prepared dish. Top each tortilla with about 1/2 cup bean mixture. Sprinkle evenly with 1/3 of cheese. Repeat layers twice, creating 2 tortilla stacks each 3 tortillas high.
- Pour water along sides of tortillas.
- Cover tightly with foil and bake 30 to 35 minutes or until heated through. Cut into wedges to serve. Serve with sour cream and black olives, if desired.
