1Preheat a large skillet over medium heat.
Add the beef curry to the skillet and cook until heated through, about 5 minutes.
Remove the beef from the skillet and set aside.
Place a tortilla in the skillet and sprinkle with cheese.
Add a portion of the beef, grilled onions, and tomatoes on top of the cheese.
Place another tortilla on top and press down gently.
Cook for 2-3 minutes on each side, or until the tortillas are golden brown and the cheese is melted.
Repeat the process with the remaining tortillas and filling.
Cut the quesadillas into wedges and serve warm.