Pre-heat oven to 350 degrees.
In a small dish, mix together ancho chile powder, oregano, brown sugar, paprika, cayenne pepper, and salt.
Rub the chicken breasts evenly with the spice mix and place in a greased 13×9 inch pan. Bake for 22 to 25 minutes, until it’s cooked through and no longer pink in the center.
Cool the chicken for about 10 minutes and then cut it into small chunks and place them in a large bowl.