Preheat oven to 200°F. It is best to use a quality sirloin tip roast from a quality butcher or meat processor. We have had great success with the sirloin tip roast from Costco. To prepare the beef roast, rub with garlic butter, salt, pepper and other seasonings to taste, such as sliced onions, etc. on roast. Place roast in roasting pan, add water to bottom of pan, and cover with lid or tin foil.
Slow roast in oven for 8-10 hours. Remove beef roast from oven and turn oven off.
Allow roast to sit and rest for at least 20 minutes after removing from oven.
Remove lid, and remove roast from pan. Save drippings.
Roast should pull apart easily with nothing but a fork. If the roast is not of sufficient quality it may still be on the tougher side. If this occurs you can still use it by slicing the roast, but it is best used with an au jus dip or gravy as a beef dip or hot beef sandwich.
Heat a frying pan or griddle to medium-high. Fry bacon until crispy (you will need one piece of bacon per bun). Wipe out pan for re-use or grab a fresh pan, heat to medium.
Butter the bun with the garlic butter and grill it butter side down until golden brown. Remove from pan. (To make garlic butter, take 1/2 cup soft butter or margarine, add 1 tbsp Johnny's garlic seasoning (from Costco), or 1 tsp garlic salt, add 1 tsp Clubhouse roasted pepper and garlic seasoning, stir well).
On the frying pan or grill, place 4 oz of roast beef arranged in a way that it would fit the bottom of the bun, drizzle with bourbon sauce, top with a slice of cheddar cheese. You may wish to cover with a lid to help the cheese melt. This takes approx 45 - 60 seconds.
Drizzle Kentucky Bourbon sauce on the bottom of the bun.
Place beef with melted cheese on the bun, tear the slice of bacon in half and place both halves on top of the cheese. Drizzle with more Kentucky Bourbon sauce. Place the top of the bun on the beef melt.