HEAT oven to 350°F.
HEAT 1 Tbsp. oil in large skillet on medium-high heat. Add meat; cook 5 min. or until browned on all sides, turning occasionally. Transfer to roasting pan. Add 1 cup broth; cover. Bake 1-1/2 hours or until meat is done (165°F), basting every 30 min.
MEANWHILE, cook and stir onions and garlic in grill pan or skillet on medium-high heat 5 min. or until crisp-tender. Remove from pan; peel garlic. About 30 min. before meat is done, blend remaining broth, tomato sauce, ancho peppers, chipotle pepper, 1/2 cup nuts, onions and garlic in blender until smooth. Heat remaining oil in medium saucepan on medium heat. Add prepared sauce; cook 15 min., stirring occasionally.
CHOP remaining nuts. Slice meat; place on platter. Drizzle with prepared sauce; top with cheese, remaining nuts and cilantro.