Cook chicken in skillet until juices run clear or just use rotisserie chicken and tear up the chicken into small pieces.
Heat 2 tablespoons of oil in a skillet over medium heat. Add in the onion and cook until soft, about 3 minutes.
Add in the garlic and cook for an additional minute,
Add in the chicken, spices, sweet corn, and black beans. Cook for a minute.
Add in the tomato and cilantro. Stir well to combine and cook for a minute more, or until warmed through. Remove the skillet from heat.
Preheat the oven to 450 degrees F.
Melt 3 tablespoons of the butter in a microwave-safe bowl.
Scoop about 3/4 cup worth of the chicken and bean mixture onto the center of each tortilla. Sprinkle with 1/4 cup of cheese each. Brush the outside of the tortilla with butter and fold the tortilla. To fold, bring in both sides, then bring the bottom upward, and then turn the whole chimichanga over, longways, to fold over the remaining top side. Move to a prepared baking sheet. Brush each chimichanga with the melted butter.
Bake for 10 minutes, then flip and butter the other side of the chimichangas. Bake for another 8 minutes, or until golden brown and crisp.