How to Make It
Season the lamb shanks with salt and pepper and dust with the flour, shaking off any excess. In a large skillet, heat the olive oil until shimmering. Cook the lamb shanks over moderately high heat, in batches if necessary, until browned all over, about 10 minutes. Transfer the shanks to a slow cooker. Add the chicken broth, dill sprigs, garlic, onion and lemon. Cover and cook on high until the lamb is tender, about 4 hours.
Transfer the shanks to shallow bowls and keep warm. Skim the fat from the cooking juices. Stir in 1 tablespoon of the chopped dill and the lemon juice and season the juices with salt and pepper. Spoon the juices along with the onion and lemon over the lamb shanks. Sprinkle with the feta and the remaining 1/2 tablespoon of chopped dill and serve with orzo.