Combine ground beef, 2 slices of crumbled bacon, 1/3 cup Bleu cheese, dry mustard, seasoned pepper and egg.
Form into 4 patties.
Butter the insides of the buns and toast them in a skillet.
Heat grill to 350 degrees and place burgers on the grill. Grill 9 minutes on each side. Internal temperature of the burger will be 160 degrees for a "well done" burger.
Place the burger on the toasted bun, add some mayo. Top with tomatoes, 2 slices of bacon and Bleu cheese.