Prepare the ground beef. Add the ground beef to a large skillet and heat over medium/high heat for 2-3 minutes. Break the ground beef up into small pieces.
Add the taco seasoning, tomato paste, water, and black beans to the ground beef and toss all the ingredients together. Cook everything together until the beef is cooked and the tomato paste and water turn saucey (about 4-6 minutes).
Remove the skillet from the heat.
Place an XL quesadilla on a cutting board and use a pizza cutter or knife to make one cut from the outside of the tortilla to the center. Flip the tortilla so the cut is on the bottom of the tortilla, facing you. You will be creating 4 quadrants in your tortilla.
Slather 1 tablespoon of sour cream over the surface of one tortilla. Then, you are going to alternate ground beef and cheese in the 4 quadrants.
Place ¼ cup ground beef in 1 quadrant, then ¼ cup cheese, then another ¼ cup ground beef, and then finally, ¼ cup more of cheese.
To fold the quesadilla, fold the first quadrant in the bottom right up by folding the ingredients on to each other. Then, fold over, and down creating a triangle shaped quesadilla.
Repeat steps 4-7 with the other tortilla. Set the quesadillas aside.
Heat a small grill skillet over medium/high heat and drizzle 1-2 teaspoons of olive oil in the pan.
Place one quesadilla in the grill pan and place a heavy pan on top of the quesadilla. Cook the quesadilla for 3-4 minutes on each side until browned and the cheese is melted.
Cook the other quesadilla and then top each quesadilla with your favorite toppings and enjoy.