Steps
1. Heat the oil in a large skillet over medium-high heat.
Add mushrooms and peppers, and cook until softened and lightly browned, about 5 minutes.
2. Add the cooked beans to the skillet, and stir to combine.
3. Place one tortilla on a plate and top with the bean mixture. Sprinkle cheese on top. Place the second tortilla on top.
4. Heat a large skillet over medium-high heat. Place the quesadilla in the skillet and cook until golden brown, about 2 minutes per side.
5. Slice and serve hot.