Tenderize steaks, if necessary, by pounding. Using a clean dish for preparation, divide mustard and spread on top of each steak. Divide mushrooms and peppers evenly on top of each steak. Roll up each steak, enclosing the peppers, and wrap each roll with 1 slice of bacon. Repeat procedure with remaining 5 steak rolls. Secure with string or a skewer. Lightly season with blended seasoning mixture.

In a Dutch oven over medium-high heat, cook the remaining 2 strips of bacon; add onion and cook until tender. Add the steaks and brown lightly on all sides. Add hot beef broth and reduce the heat. Braise the steaks until an instant-read thermometer registers an internal temperature of 140 degrees F.

Remove the steaks from the Dutch oven. Add the flour to the reduced stock and whisk to make a brown sauce. Return steak rolls to Dutch oven and keep warm until serving time. Internal temperature at serving time may be 160 degrees F.

To serve: remove string or skewer. Cut steak diagonally to show colors of peppers and mushrooms. Drizzle sauce over top.