On a slice of beef, ⅓ in, place a slice of pickle, onion wedge, slice of bacon, squirt of mustard, and salt and pepper. Roll the beef around the pickle, onion, bacon... and secure with a toothpick or two. Continue this with all the slices of beef.

In a medium bowl, whisk together all the ingredients for the gravy.

Spray the pot of your crock-pot or instant pot with non-stick cooking spray. Pour in half of the gravy. Place the rouladen in the pot and pour the remaining gravy on top.

Let cook on low for 5-7 hours if using a crock-pot. For the instant pot, set the valve to sealing, push the pressure cook button and the timer for 45 minutes. When it is done, allow it to self release for 5-10 minutes then turn the valve to venting. When the silver button is up, remove the top.

Remove the rouladen to a serving plate. If the gravy is not thick (it usually isn't), pour it in a 12 inch skillet on the stove and turn on medium heat. Add a tablespoon or two of brown gravy powder, flour, or cornstarch - flour will work just fine - and whisk until it thickens and there are no lumps. Pour some of the gravy over the rouladen and the rest in a gravy boat for serving.