Lay a slice of beef rouladen flat on your work surface. Spread a thin layer of mustard evenly over each slice. Sprinkle with salt and pepper to enhance the flavors.

On each slice of beef, place a slice of turkey bacon, followed by some chopped onion and a few pickle strips.

Carefully roll up the beef tightly, starting from one end to the other. Secure each roulade with toothpicks or a piece of kitchen twine to keep the filling inside.

In a large skillet, heat the vegetable oil over medium heat. Once hot, add the roulades and sear them on all sides until they are nicely browned.

Add the beef broth and the bay leaf to the skillet. Bring everything to a gentle simmer. Cover the skillet and allow to cook for about 1.5 to 2 hours, or until the meat is tender.

Once the roulades are cooked, remove them from the skillet and keep them warm on a plate, covered with foil if necessary.

To thicken the sauce, stir the flour into the hot broth, whisking until smooth. Allow it to simmer for a few moments until it reaches your desired thickness.

Serve the rouladen with the rich sauce drizzled on top and garnish with fresh parsley for a pop of color.