01 -
Set Blackstone grill to medium-high heat (approximately 200°C). Spread vegetable oil evenly over the cooking surface.
02 -
Distribute diced skirt steak and onion onto the oiled grill. Season with onion powder, salt, and black pepper. Sauté for 4 to 8 minutes per side, stirring occasionally, until the steak is deeply browned and cooked through.
03 -
Transfer cooked steak and onions to one side of the grill. Adjust heat to medium.
04 -
Lay flour tortillas flat on the cleared portion of the grill. Evenly scatter half the shredded mozzarella and Monterey Jack cheese on each tortilla. Spoon cooked steak and onions over the cheese, then top with remaining cheese.
05 -
Fold each tortilla over the filling to form a half-moon. Cook for 1 to 2 minutes until the underside is golden brown.
06 -
Carefully flip each quesadilla and cook for another 1 to 2 minutes, ensuring both sides are crisp and cheeses have fully melted.
07 -
Transfer quesadillas to a cutting board, slice into wedges, and serve immediately while hot and crispy.