Lay the beef out flat. If it is thick, cover it with plastic wrap and gently pound it thinner. You want it flexible enough to roll without fighting you.

Season both sides with salt and pepper. Spread mustard on the top side, not too thick, just a nice even swipe.

Add fillings: place a strip of bacon on each piece, then a little onion, then a pickle spear. Roll it up tightly from the short end, like you are rolling a little burrito.

Secure the roll with toothpicks or kitchen string. Toothpicks are easier on a weeknight, just remember how many you used so you can remove them later.

Heat oil in a heavy pot over medium heat. Brown the rolls on all sides. Do not rush this part. Browning builds the flavor for the gravy.

Once browned, push the rolls to the side for a second and stir in tomato paste if you are using it. Let it cook for about 30 seconds, then pour in broth and water. Scrape up the browned bits from the bottom.

Add paprika and bay leaf. Bring it to a gentle simmer, cover, and cook low for about 90 minutes. If the liquid gets low, add a splash more broth or water.

When the beef is tender, remove the rolls to a plate. If you want a thicker gravy, stir in the flour slurry and simmer a few minutes until it looks right.

Put the rouladen back in the gravy for a minute so everything stays warm, then serve.