Prep the Filling: Heat 1 tablespoon of olive oil in a skillet over medium heat. Add the chopped red onion and diced bell pepper. Sauté for about 5 minutes, until softened. Add garlic, cumin, chili powder, salt, and pepper, and cook for another minute until fragrant.

Mix the Beans: In a mixing bowl, combine the black beans with the sautéed mixture. Use a fork to mash the beans slightly, then stir in half of the shredded cheese.

Assemble the Quesadillas: Heat a non-stick skillet over medium heat and add a little olive oil. Place one tortilla in the skillet, and spoon some of the bean mixture onto half of the tortilla. Sprinkle with the remaining cheese. Fold the tortilla over to create a half-moon shape.

Cook Until Crispy: Cook for 3-4 minutes on one side until golden brown, then flip and cook for another 3-4 minutes on the other side. Repeat with the remaining tortillas.

Serve: Let the quesadillas cool slightly before slicing into wedges. Garnish with fresh cilantro and serve with sour cream and salsa on the side.