Combine rub ingredients in a bowl. Then apply to the surface of the beef shanks.
Get your smoker to 250F.
Once at 250F, place your beef shanks on the smoker. Add a few chunks of your favorite hardwood - I used pecan.
Smoke until 175F internal or when you're happy with the bark.I smoked the beef shanks for 3 hours.
Wrap your beef shanks in aluminum foil so that no steam can escape.If you have some beef stock or beef broth, add a few tablespoons to the wrap. Once wrapped, return back to the smoker.
Take the beef shanks off the smoker when they're tender. For me this happened after roughly 2 hours of smoking.You want your probe thermometer or toothpick to glide in and out of the meat with no resistance.
Rest the shanks wrapped for 30 minutes.
After 30 minutes, remove the shanks from the bone and set the bones aside.Use a sharp knife like a cleaver and chop the shank meat up. While you're chopping up the shank meat you'll notice bits of tendon. You'll want to remove this and throw them away as they're not appetizing and are quite chewy. Once the meat is chopped up, add the bone marrow from the bone and mix it into your chopped beef. Then enjoy!