Southwestern Mushroom Monterrey Quesadillas

1 Tbsp tomato paste
1 Tbsp apple cider vinegar
1/4 tsp chipotle pepper sauce
1/4 cup barbecue sauce
2 Tbsp cooking oil, divided
1 lb. mushrooms, cleaned and diced 
1 onion, diced
4 tortillas (8 inch size)
1 cup Monterrey Jack cheese, shredded

In a bowl, combine the tomato paste, apple cider vinegar, chipotle pepper sauce, and barbecue sauce, stirring until smooth; set aside.
In a large skillet over medium heat, heat 1 tablespoon cooking oil. Once the oil is heated, add the mushrooms and cook for 5 minutes. Now add the onion and cook until mushrooms and onions are beginning to brown. Dump this mixture into the bowl with the sauce mixture and stir until thoroughly combined.
Lay each tortilla out onto a cutting board or other clean surface, and spread 3 tablespoons cheese on each tortilla, covering half.  Use about 1/2 cup of the sauce/mushroom mixture and spoon on top of the cheese on each tortilla. Fold each tortilla in half and gently flatten.
Use the remaining 1 tablespoon oil and heat it over medium high heat in the same skillet (make sure the skillet has been wiped out.)  Add 2 quesadillas and cook 2 minutes or until browned slightly, then flip and brown the other side. Repeat until all quesadilla’s have been cooked. Remove to plates, cut in half and serve warm.