In a large skillet, heat 2 teaspoons of light olive oil over medium-high heat. Add the thinly sliced beef, seasoning with sea salt and black pepper, and cook for about 4-5 minutes until fully cooked.

In the same skillet, add a splash more olive oil, then toss in chopped onion, diced red pepper, green pepper, and mushrooms. Sauté over medium heat for 5-7 minutes until tender.

Return the cooked beef to the skillet, add minced garlic, and stir to combine. Heat through for 1-2 minutes.

Spread a thin layer of mayonnaise on the flour tortillas if desired. Divide the beef and vegetable mixture evenly among the tortillas, topping with slices of provolone cheese. Fold each tortilla in half.

Wipe the skillet clean and return it to medium heat. Cook the quesadillas for 3-4 minutes on one side until golden, then flip and cook for an additional 2-3 minutes until the cheese melts.

Remove from the skillet and let rest for a minute. Slice each quesadilla into triangles and serve warm.