1. Preheat oven to 350 degrees F. Wrap tortillas tightly in foil. Heat in oven about 10 minutes or until heated through.
2. Meanwhile, for filling, in a large saucepan, cook onion and garlic in the 1 teaspoon hot oil until tender. Stir in chicken, black beans, 1/2 cup bottled salsa, the cheese, and 2 tablespoons cilantro.
3. For each flauta, spoon about 1/2 cup filling across each warm tortilla about 1-1/2 inches from one edge. Roll up tortillas as tightly as possible. Secure with wooden toothpicks.
4. In a very large, deep skillet, heat 1-1/2 inches of cooking oil to 365 degrees F. Fry flautas, two at a time, for 2 to 3 minutes or until crisp and golden brown, turning once. Drain on paper towels. Keep fried flautas warm in a 300 degrees F oven while frying remaining flautas.
5. To serve, remove toothpicks. Halve flautas crosswise. If desired, serve with guacamole, salsa, sour cream, and cilantro.
6. Baked Flautas: Prepare filling and shape flautas as directed. Place flautas on a large baking sheet and brush with 1 tablespoon cooking oil. Bake in a 350 degrees F oven for 30 to 40 minutes or until golden brown and heated through. Serve as directed.
7. Make-Ahead Directions: Prepare filling and shape flautas as directed. Cover; chill for up to 24 hours. Fry or bake as directed. Makes 6 flautas.