In a large skillet, heat 2 teaspoons of light olive oil over medium heat. Add the thinly sliced beef, seasoning with sea salt and ground black pepper. Cook beef for 4-5 minutes until browned. Remove and keep warm.

In the same skillet, add more olive oil if needed. Toss in chopped onion, diced mushrooms, and peppers. Sauté for 5-7 minutes until tender and caramelized.

Return cooked beef to the skillet with the vegetables. Add minced garlic and cook for 2-3 minutes until heated through.

Optionally spread mayonnaise on one side of each flour tortilla. Divide the meat and vegetable mixture evenly across half of each tortilla. Fold each tortilla.

Layer provolone cheese over the filling on each tortilla. Fold the other half of each tortilla over the filling.

Heat another teaspoon of light olive oil over medium heat in the skillet. Cook folded quesadillas for 3-4 minutes per side until golden brown and crispy.

Transfer to a cutting board, allow to cool for a minute, then slice into wedges. Serve with optional toppings.