Preheat the oven to 350 degrees F.
Remove the osso buccos from the packaging and coat lightly with melted butter or oil. Add remaining oil to a cast iron skillet, sheet pan, or dutch oven. Put the osso buccos over the oil.
Bake for 15 minutes at 350, until nicely browned. During the last five minutes, throw in the chopped garlic.
Remove from oven. If you're using a dutch oven that can work on the stovetop, don't worry about moving the beef to another pan. Otherwise, remove the beef from the pan and place in a crock pot or a soup pan. Add about a cup of water to the oven pan and swish it around to pick up the oils and garlic, then pour in with the osso buccos. Add remaining water, tomato sauce, onion, lemon juice, and herbs. Don't worry about the stems on the herbs--you can remove these later, after all the leaves have boiled off and flavored the soup. Next, sprinkle in the spices.
Place on the stovetop or in the slow cooker and turn to medium heat. Cover and allow to simmer for about 2 hours. Add water as needed. The osso buccos should always be about halfway covered in water.
After cooking 2 hours, chop the carrots, sweet potatoes, and celery and add to the soup. Turn up heat to high and boil for about 30 minutes (it may take longer in a slow cooker) until vegetables are tender.
Remove bones from soup (or leave them in there and just eat around them).
This soup can be refrigerated and reheated for several days, or you can freeze it in an airtight plastic container for a few weeks (I wouldn't recommend longer than that because it might affect the flavor). You can also boil away most of the liquid and make pot pies with any leftovers.