Preheat oven to 400°F (200°C). Line a baking sheet with foil or parchment.
In a bowl, combine shredded chicken, cheese, salsa, green chiles, cumin, chili powder, salt, and pepper.
Warm tortillas slightly to make them easier to fold.
Spoon chicken mixture onto the center of each tortilla.
Fold in sides and roll up tightly like a burrito.
Place seam side down on the baking sheet.
Brush each chimichanga with melted butter or oil.
Bake for 20–25 minutes, flipping halfway through, until golden brown and crispy.
Serve hot with your favorite toppings.