In a food processor, combine ancho, onion, garlic, orange juice, lemon juice, achiote, salt and oregano. Process to a paste. Add oil to the paste and mix well. Combine paste with turkey and marinate for 8 hours. Thread turkey onto skewers. Grill or broil for 5 minutes per side or until done. Place turkey cubes in a tortilla, cover with black beans and serve.