Heat a splash of olive oil in a non stick pan on med heat, add the sliced onion and cook until translucent but not browned. Add the cooked onion to the beef stock, season with salt, pepper, and thyme.

Place the roast in your slow cooker, pour the stock over the top of the roast. Cover and cook on Low setting for 8 hours or High setting for 4 hours. Leave the cover on, you want this to be falling apart beef!

Preheat your oven to 180 C.

Remove 3 cups of liquid from the slow cooker and add to a sauce pan. Heat on medium and bring to a boil, then reduce to a simmer and cook until reduced by half, about 10 minutes.

Remove beef from the slow cooker and place on a plate and shred with a fork.

Place the sandwich rolls on baking sheet and spoon meat on to the rolls, top each roll with Provolone cheese. Cover with foil and bake for 5 minutes or until the cheese is melted. Serve with the sauce on the side for dipping.