Heat 2 teaspoons of olive oil in a large skillet over medium-high heat until shimmering.

Add cheesesteak beef and cook for about 4-5 minutes, until browned. Drain excess grease and keep warm.

Sauté chopped onions, red and green bell peppers, and mushrooms for about 4-5 minutes until softened.

Return the cooked beef to the skillet. Add minced garlic and stir until fragrant, about 30 seconds.

Spread mayonnaise on one side of each flour tortilla. Pile beef and vegetable mixture on one half, then top with provolone cheese.

Fold the tortilla in half over the filling and press down to secure the contents inside.

In the skillet, heat another teaspoon of olive oil. Cook the folded quesadilla for about 3-4 minutes on each side until golden brown and crispy.

Remove the quesadilla from the skillet and let it sit for a minute before slicing into wedges. Serve warm.