Combine flour and pepper in pie plate. Add meat, 1 shank at a time; turn to evenly coat both sides with flour mixture, shaking off excess. Heat 3 Tbsp. oil in Dutch oven or large deep skillet on medium heat. Add meat, in batches; cook 3 to 5 min. or until evenly browned on all sides, turning frequently. Place in 4-L casserole dish sprayed with cooking spray.