Step 1
Preheat oven to 450 degrees F (230 degrees C).
Step 2
Place lamb shanks into a large bowl; drizzle with olive oil. Sprinkle with salt black pepper smoked paprika cinnamon and rosemary. Toss the lamb shanks to spread oil and seasonings over the meat.
Step 3
Spread onion slices and garlic cloves into the bottom of a heavy 9x12-inch baking dish. Lay lamb shanks over onions and garlic.
Step 4
Bake lamb in preheated oven for 30 minutes. Reduce oven temperature to 200 degrees F (95 degrees C).
Step 5
Combine chicken broth and saba in a bowl. Pour mixture over the lamb shanks. Cover baking dish tightly with foil and place baking dish on a baking sheet.
Step 6
Bake lamb in the oven until a knife pierces the meat easily 2 1/2 to 3 hours. The meat will be tender but not falling off the bone. Use tongs to turn the shanks over in the pan sauce. Increase temperature to 350 degrees F (175 degrees C).
Step 7
Return shanks to oven and bake uncovered until meat is fork-tender and the sauce has thickened slightly 10 to 15 minutes. Turn shanks over in the sauce after 10 minutes and check for tenderness; if still not tender enough return to oven for 10 to 15 more minutes and test again.
Step 8
Transfer lamb shanks to a bowl and keep warm. Strain pan juices into a saucepan and place over medium heat. Bring to a boil and cook stirring often until thickened about 5 minutes. Skim any excess grease from top of sauce. Taste and season with salt; stir in fresh rosemary. Serve sauce drizzled over lamb shanks.