Preheat oven to 425 degrees F.
Coat baking sheet well with cooking spray, and place chicken on it. Sprinkle lightly with kosher salt and cayenne or black pepper.
Bake chicken for 20 minutes or so, until instant thermometer reads 160 degrees. Remove chicken and cut into 1" pieces.
Meanwhile. combine beans, cheese, chiles, green onions and cumin in large bowl.
Add chicken to other ingredients, and toss well.
Roll up chicken mixture in tortillas. Brush chimichangas lightly with oil.
Bake chimichangas for about 20 minutes, until they are crisp and beginning to brown. Turn over and allow to cook for 5 more minutes.
Remove from oven and serve with sour cream, pickled jalapenos and salsa.