Preheat oven to 400 °F (200 °C). You'll need Cheesecloth and a 2-quart Baking Dish (Preferably one that is at least 2.5 " deep and no larger than 9X9) * Make sure you have the stuffing fully cooked before beginning and let it cool before stuffing the roast.
Whisk the teriyaki and barbecue sauce together. Set aside.
Add all of the roast ingredients*except the vital wheat gluten* to a blender or food processor. Blend until everything is broken down and smooth. Pour into a large mixing bowl.
Add the vital wheat gluten to the wet mixture. Stir with a fork or spoon until a dough starts to form. Now, using your hands knead dough until fully combined (*the dough will be thick & elastic).
Place dough on a smooth surface and knead for 1-2 minutes more. Roll it out with a rolling pin to approximately 10x7. Roll from the middle outwards then flip and repeat. Also, roll both vertical and horizontal until you've reached desired size/shape.
Lightly pack the stuffing into a log shape and place in the middle of the dough. Now, bring both ends of the dough together over the stuffing and pinch to close well. Continue to pinch the rest of the dough closed through the middle and ends. Pinch well too avoid separation. (*If you have excess dough at the ends, just trim it and pinch closed again. You want the stuffing to reach the ends to avoid a gap inside).
Now tightly wrap the roast with at least two layers of cheesecloth (more if the fabric is thin). Twist the ends and tie tightly with twine. Trim off excess cloth.
Place the roast in the casserole dish and pour about 1" of broth inside. Add fresh herbs and bay leaves to the broth if desired. Now, place in the oven and bake for 1 1/2 hours. Rotate the roast every 20 minutes for even cooking. (If broth cooks off during baking, add 1/4 cup more each turn, but let it cook down during the final 20 minutes)
Poke the roast to check for doneness- it should be somewhat firm on the outside, but it will still be a little soft on the inside. You just don't want it to be so soft that it caves in when you poke it - then it will need to cook longer (the roast firms up more when it's baked unwrapped with glaze). When done, remove from oven and carefully unwrap the cheesecloth (*if it sticks to the roast, you can use a splash of vegetable broth to remove it). Pour out any remaining broth in the dish and discard.
Place the roast back in the baking dish and liberally brush the tops and sides with the glaze. Bake for 5 minutes until the glaze becomes tacky (*watch carefully to prevent burning). Now flip the roast and glaze top and sides again. Bake for another 5 minutes. Remove from oven and let the roast sit for at least 10 minutes before cutting.