Season the steak with salt, pepper, chili powder, cumin, and garlic powder. Heat 1 tablespoon olive oil in a skillet over medium-high heat. Cook the steak for 3-4 minutes per side to desired doneness. Let rest for 5 minutes and slice thinly against the grain.

In the same skillet, heat the remaining tablespoon of olive oil over medium heat. Add sliced bell pepper and onion, sauté for 5-6 minutes until softened and golden. Season with salt and pepper to taste.

Wipe the skillet clean and reduce heat to medium-low. Add 1 tablespoon of butter, melt and coat. Place one tortilla in the skillet, sprinkle half with ½ cup of cheese, layer with steak and vegetables, top with another ¼ cup cheese and fold.

Cook the quesadilla for 2-3 minutes until golden brown. Flip and cook for another 2-3 minutes until cheese is melted. Remove and let rest for 1 minute. Slice into wedges and serve immediately.