Bake. Place in the oven and bake for 15-20 minutes turning the bacon halfway through. Start keeping a close eye on it around 13 minutes to ensure it doesn’t burn.
Add roast beef, cheese, and bacon Place a layer of roast beef over the bottom buns and top with a layer of cheddar cheese. Finish with a layer of chopped brown sugar bacon and place the top buns on the sandwiches.
Make butter mixture – In a small bowl mix together melted butter, Dijon mustard, sesame seeds, dried minced onions, and Worcestershire sauce.
Cover and bake. Cover the dish with foil and bake for 15 minutes, then remove the foil and continue baking for another 5 minutes or until cheese is melted.