Heat 2 teaspoons of olive oil in a skillet over medium-high heat. Add thinly sliced cheesesteak beef and cook for 3-4 minutes until browned. Drain excess grease and keep beef warm.

Add 1 teaspoon of olive oil to the same skillet, heat until shimmering. Toss in chopped onions, red and green bell peppers, and mushrooms. Sauté for 5-7 minutes until softened.

Return beef to skillet with sautéed vegetables. Add minced garlic and cook for 1-2 minutes until fragrant.

Lay out flour tortillas. Spread mayonnaise on one side of each tortilla. Distribute beef and vegetable mixture on the mayonnaise side.

Sprinkle provolone cheese over the filling. Fold each tortilla in half to encase the filling.

Wipe the skillet clean, drizzle olive oil, and cook folded quesadillas for 3-4 minutes per side until golden brown.

Once cooked, remove from skillet, let rest for a minute, then slice into wedges and serve warm.