Good quality beef, cut into long, thin slices, about 2" x 8"
Bacon, one slice for each roll you want to make
Lengthwise dill pickle slices
2 cups beef broth
2 Tbsp flour + 1/4 cup cold water
Cook bacon in a skillet JUST until the edges start to curl (do not cook all the way, or even close to it). Remove bacon to a plate, remove skillet from heat, and keep the bacon grease in the skillet for cooking the rolls.
Lay out beef strips, spread a little dijon mustard on each slice of beef, lay a slice of dill pickle and a slice of bacon on it, roll up and secure with a couple toothpicks.
Reheat the skillet that you cooked the bacon in, over medium-high heat. Add the rolls and cook for about 10-15 minutes, or until deeply browned on all sides. They won't be cooked through yet, most likely.
Leave the rolls in the pan, and add 2 cups of beef stock, scraping the bottom of the pan to loosen all the tasty bits. Bring to a boil, then reduce heat, cover and simmer for 20 minutes. Remove rolls to a serving plate. Whisk together the flour and cold water, then add it to the beef stock, whisking constantly, until it boils and thickens.
Serve the rolls with plenty of gravy and mashed potatoes.