Rub the lamb with the spice blend and place in a slow cooker. Add all the chopped vegetables and garlic cloves over and around the lamb. Pour in 4 of the 6 bottles of stout beer, then add enough water just to cover the lamb. Turn the slow cooker on high, cover, and cook for 4 to 5 hours, or until the lamb easily shreds from the bone.

While the lamb is braising, combine the mayonnaise and teriyaki in a small mixing bowl and store in the refrigerator until ready to use.

When the lamb is within 1/2 hour or so of being done, start reducing the other 2 bottles of stout in a small pot or saucepan on medium to high heat, allowing the beer to reduce by 1/2. When fully reduced, add the sugar and stir. Taste your reduction; depending on your favorite stout you may need to adjust the amount of sugar to counteract the bitterness of the beer. When seasoned to your liking, turn the heat down to low and cover.

When your lamb is ready (the meat is tender and shreds easily), remove the leg from the slow cooker and place in a baking pan. Allow the lamb to rest and cool while transferring your braising liquid from the slow cooker into a large pot. Be sure to pour the liquid through a strainer to remove the cooked vegetables. Discard the vegetables and skim clear the fat and oil from the top of the braising liquid. Put over medium-high heat and reduce by 1/4. When reduced, add the au jus mix, to taste. Stir thoroughly and place over medium heat.

The first step of shredding your lamb is removing the three main bones (while shredding, wear gloves and have a bowl of ice water to cool your hands as the meat will still be very hot). Next, remove all non-edible connective tissue and cartilage. As you begin shredding the meat you will be able to identify what is good meat and what isn't. After discarding the bad from the good, you are ready to shred the rest of the meat.

Place 6 to7 ounces of shredded lamb per serving in a saute pan over medium-high heat. Add a small ladle, or about 1/4 cup, of the stout reduction to the pan and cover. When the lamb comes back up to temperature, stir, then top with some shredded cheese and cover to melt.

Toast your hoagie rolls to your liking and spread the teriyaki mayo on the rolls. Place the lamb on a hoagie. Cut in half and serve with the au jus and your favorite side.