Heat a large skillet over medium-high heat and add 2 tablespoons of olive oil. Sear the thinly sliced beef seasoned with sea salt and black pepper for 4 to 5 minutes until no longer pink. Transfer beef to a plate and keep warm.

In the same skillet, add the remaining olive oil, then sauté chopped onion, diced peppers, and mushrooms for 5 to 7 minutes until softened and slightly caramelized.

Return the cooked beef to the skillet with the vegetables, add minced garlic, stir, and cook for another 2 minutes until fragrant. Adjust salt and pepper to taste.

Lay tortillas flat, and if using mayonnaise, spread it on one side of each tortilla.

Place two slices of provolone on one half of each tortilla, then evenly divide the beef and vegetable mixture on top.

Add another slice of provolone on top before folding the tortillas in half.

Wipe the skillet clean, return to medium heat, and drizzle oil if desired. Cook each folded quesadilla for 3 to 4 minutes per side until golden brown and the cheese is melted.

Let cooked quesadillas rest for a minute before slicing into wedges. Serve warm.