Cut boneless skinless chicken breasts into bite-sized pieces. Toss with chili powder, ground cumin, salt, and freshly ground black pepper until well-coated.

Heat 2 tablespoons of olive oil in a non-stick skillet over medium-high heat for about 1-2 minutes until shimmering. Add the chicken chunks and cook for approximately 6 minutes until golden brown and fully cooked.

Add sliced bell peppers and chopped red onion to the same skillet, sauté for about 6 minutes. Add minced garlic during the last minute.

Return the cooked chicken to the skillet, drizzle fresh lime juice, and toss everything until well-combined.

Melt 2 tablespoons of butter in a separate skillet. Brush one side of each tortilla with the melted butter.

Place a tortilla in the skillet, sprinkle half of the cheese, add the chicken-vegetable filling, fold the tortilla in half.

Cook the filled quesadilla for 2-3 minutes until golden brown, flip and cook for another 2-3 minutes.

Remove from skillet, let it cool slightly before cutting into wedges. Serve warm with optional toppings.