Yams: cut into 2 chunks and boil until lightly tender. Drain, rinse in cold water, peel and set aside.
Mix granulated garlic and pepper with flour in plastic bag. Dredge pork chops and saute in oil in large pan until lightly browned. Remove from pan and set aside.
In the pan the pork was cooked in, saute onions and garlic until onions are translucent. To pan add beef stock, orange juice, red pepper flakes, cumin and oregano. Return pork to pan. Bring to a boil, reduce heat and simmer covered for 40 minutes, turning pork halfway through. Add yams and cover, simmer for another 5 minutes.
Remove pork and yams from pan, set aside and keep warm.
Whisk together lemon juice, cornstarch and orange peel. Pour into pan juices. Bring to a boil and simmer, stirring, until thickened, about 3 minutes. Return pork and yams to pan. Cover and simmer for 3-5 minutes.
Plate pork and yams with generous helping of pan juices. Garnish with orange slices and serve.