Dice and cook the bacon for about 10 minutes. Stirring occasionally to prevent burning.
1 pound bacon
Once the bacon is done, remove it from the pan and put it on a plate with paper towels to allow it to drain. Remove all the grease in the pan from the bacon, reserving about 1-2 tsp.
Add 1 Tbs of butter to the pan, and then add the sliced mushrooms and onions. Let those cook down for about 5 minutes.
8 ounces white mushrooms, 1-1/2 tablespoons butter, 1 large yellow onion
Cut the roast beef into long slices, then add to the pan and cook for 5 minutes.
1 pound cooked roast beef
For the sauce, mix the blue cheese, mayonnaise, and horseradish sauce together in a bowl.
1/2 cup mayo, 1/4 cup horseradish sauce, 1/4 cup blue cheese crumbles
Crumble the bacon and add to the cooked roast beef.
Serve on sub buns with lettuce, tomatoes, and the blue cheese sauce. Enjoy!
6 sub sandwich buns, lettuce and tomato for topping