Heat oven to 325. Whisk together 1/4 cup flour with plenty of salt and pepper to season a roast.
Dust the roast with this mixture.
Heat a few tbsp of oil over high heat in an oven safe pan with a lid and allow to get very hot. Brown the roast on all sides. Move to a plate.
Add the vegetables to the pan and sprinkle with salt and pepper. Allow to cook, stirring occasionally until they are beginning to become tender, about 3-5 minutes.
Add the remaining 2 tbsp of flour sprinkled over the vegetables and mix well.
Slowly add the stock while whisking to prevent the flour from forming lumps.
Add the roast back to the pan and add the bay leaves. If the roast is not submerged most of the way, add more stock or water to cover it most of the way.
Bring to a boil, cover and place into the oven. Cook for 2 hours, check and add more liquid if needed to keep the meat submerged. Cook another 1-2 hours until the meat is fork tender.
Remove from the oven, let cool for 30 minutes and then move the meat to a container. Strain the gravy through a strainer into the container as well.
Place in the fridge overnight.
Slice the meat as thinly as possible. Heat the gravy in a large skillet on the stove and taste and season as needed. Add the sliced meat and allow to warm through.
Toast the rolls slightly and then spread mayo on them and season lightly with salt and pepper. Add the meat, gravy, lettuce tomato and pickles and serve.