Pat the lamb shanks dry
Season generously with salt and pepper
Heat oil in a heavy pot or Dutch oven over medium-high heat
Brown the lamb shanks on all sides
Remove the shanks and set aside
Sauté chopped onions, carrots, and celery in the same pot
Add garlic and cook briefly
Stir in tomato paste and cook for a minute
Deglaze with red wine, stock, or water
Add herbs such as rosemary, thyme, and bay leaves
Return the lamb shanks to the pot
Add enough liquid to come partway up the shanks
Cover and braise in the oven at low heat until tender
Turn the shanks occasionally during cooking
Cook until the meat is fork-tender and falling off the bone
Remove the shanks from the pot
Reduce the sauce if needed
Serve the lamb shanks with the sauce spooned over them