Season the steak generously with salt, pepper, chili powder, cumin, and garlic powder. Heat a skillet over medium-high heat and add olive oil. Sear the steak for 3–4 minutes on each side until desired doneness, then remove to rest.

In the same skillet, add more olive oil if needed and sauté the sliced bell peppers and onions over medium heat for 5–6 minutes until soft and caramelized. Remove from pan and keep warm.

Wipe the skillet clean, melt butter over medium heat, and place a tortilla in the skillet. Sprinkle cheese on half, add steak and vegetables, and another layer of cheese. Fold the tortilla over.

Cook the quesadilla for 2–3 minutes on one side until golden-brown, then flip and cook for another 2–3 minutes until crispy and cheese is melted.

Let the quesadilla rest for a minute before slicing into wedges. Repeat with remaining tortillas and filling.