Drain and rinse the black beans. In a mixing bowl, combine the rinsed beans with a ripe avocado. Mash the avocado until creamy, then add a squeeze of fresh lime juice.

Take a tortilla and spread a generous amount of the avocado and black bean mixture on one half. Sprinkle a layer of Monterey Jack cheese over the filling. Fold the tortilla in half and press down gently.

In a large skillet, heat a small amount of olive oil or butter over medium heat. Place one folded quesadilla in the skillet and cook for 2-3 minutes until golden and crispy. Then flip to the other side.

Using a spatula, carefully flip the quesadilla and cook for an additional 2-3 minutes until both sides are golden.

Repeat the cooking process with any remaining assembled quesadillas, adding oil or butter as needed.

Slice each quesadilla into wedges and serve immediately with fresh salsa or guacamole.