Preheat oven to 400 degrees. Lightly brush both sides of tortillas with 2 teaspoons oil and place on a rimmed baking sheet. Bake until golden and crisp, 10 minutes. Remove, and top each tortilla with 1/4 cup refried beans, and then sprinkle with some shredded cheese. Return to oven. Bake until cheese is bubbling, about 3 minutes. Remove from oven and set aside.

In a large skillet, heat 1 teaspoon oil over medium-high. Add half of the diced red onion and cook 3-5 minutes or until softened. Add chicken, chili powder and lime juice. Season to taste with salt and pepper. Cook until chicken is warmed through (about 2 minutes).

Then divide chicken among the tortillas and place on top of the melted cheese. Continue to layer on the lettuce, diced tomato, avocado, remaining onion, and cilantro. Serve warm.