Ingredients

• 1 large boneless, skinless chicken breast (about 8 ounces)
• Kosher salt and freshly ground black pepper
• 4 tablespoons vegetable oil or lard
• 3 tablespoons unsalted butter
• 5 ounces white mushrooms, sliced (about 3 cups)
• 1/2 teaspoon ground cumin
• 1/2 medium onion, finely chopped
• 3 cloves garlic, minced
• 1/2 pickled jalapeno, minced, plus 1 tablespoon pickling juice
• 1 19-ounce can black beans, rinsed and drained
• 2 8-inch flour tortillas
• 2 cups grated white Cheddar cheese (about 8 ounces)
• Guacamole and Salsa, for serving, optional

Instructions

1. Season chicken breast with salt and pepper to taste. Heat a 10-inch skillet over medium heat; add 1 tablespoon oil or lard. Cook chicken until browned on both sides and firm when gently pressed with fingertip, about 10 minutes total. Cool slightly; tear chicken into bite-size pieces.
2. Melt 1 tablespoon butter in skillet over medium heat. Add mushrooms, 1/2 teaspoon salt, cumin, and black pepper, to taste. Cook, stirring occasionally, until mushroom's moisture releases and evaporates, about 4 minutes. Transfer to a small bowl.
3. Add remaining 3 tablespoons oil or lard to skillet. Add onion, garlic, jalapeno and jar juices, and remaining 1/2 teaspoon salt. Cook until onion is translucent, about 5 minutes. Add beans and mash until almost smooth. Set aside.
4. Place tortillas on work surface and spread 1/4 of bean mixture on one side of each tortilla (reserve leftover bean mixture for later use). Top with 1/4 of cheese, half of chicken, and half of mushrooms. Sprinkle with remaining cheese. Fold tortillas over to encase filling.
5. Heat remaining 1 tablespoon butter in a skillet, fry each quesadilla until golden on both sides, about 4 minutes. Cut into wedges with a pizza wheel or serrated knife. Serve with guacamole and salsa.