Add the salt and pepper to the flour and dust the lamb shanks. Add the oil to a pan and let the pan get hot. Once it is hot, sear the lamb shanks on all sides so that they are crisp and brown. Remove the shanks from the pan and put them aside on a plate cover with aluminum foil. Add the onion, carrot and celery to the pan and saute them for a few minutes. Add the tomato paste and stir to combine. Stir in the red wine and cook for a few minutes. Add the beef broth, stir and let it come to a boil. Now add your rosemary and bay leaves. Return the lamb shanks to the pan and spoon the vegtables and sauce over the shanks.
Cover the pan and cook in the oven for 3 hours at 325 degrees F. Occassionally turn the lamb shanks over while cooking.
After 3 hours or until shanks are tender, take them out from the sauce and cover with foil. Cook the sauce so it reduces to half the amount. Return the shanks and now season with salt and pepper, tobasco and worcesteshire sauces to taste.
This dish goes excellent with some garlic mashed potatoes!