Preheat the oven to 350°. Tie a piece of kitchen twine around the thickest part of each lamb shank. Tie a second piece about 2 inches above the first string. (The twine will keep the meat on the bone.) Season the lamb with salt and let stand at room temperature 1 hour.
In a large Dutch oven with a lid, heat the oil over medium-high. Add the lamb and cook until browned all over, 3 to 4 minutes per side. Transfer to a plate. Add the onion, carrots, celery and garlic to the Dutch oven. Reduce the heat to medium and cook, stirring often, until the vegetables soften, 8 to 10 minutes. Add the cinnamon sticks, thyme, star anise, juniper berries, if using, the cumin and crushed red pepper. Cook, stirring often, until the mixture is fragrant, about 5 minutes.
Add the tomatoes and From-Scratch Red Wine Vinegar and cook, stirring often, until the sauce is deep golden brown, 10 to 15 minutes. Add the wine and cook, stirring often and scraping up browned bits, until the liquid is reduced by half, about 3 minutes. Add the stock. Bring to a boil over high. Return the lamb and any juices to the Dutch oven. Cover, transfer to the oven and braise until fork tender, 1 1/2 to 2 hours.
Transfer the lamb to a plate. Strain the braising liquid into a large bowl. Return the lamb to the Dutch oven. Add enough braising liquid to come a quarter way up the lamb, and heat over medium-high. Using a large spoon or ladle, spoon the liquid over the lamb until the sauce reduces slightly and glazes the meat, 20 to 30 minutes.
Meanwhile, in a large pot, boil the remaining braising liquid over medium-high until the liquid coats the back of a spoon, about 30 minutes. Serve with the lamb.