Cook the bacon in a large skillet until done but not crispy. Remove and let drain and cool on paper towel.

Lay the beef slices out on a flat surface and season well with salt and pepper on both sides.

Squirt one side of the meat with the yellow mustard. Don't be shy with it. Spread out evenly.

Divide the onion, pickles and cooked bacon between the meat slices.

Roll meat up, securing with toothpicks.

Melt butter in a large skillet over medium-high heat.

Add the rouladen and brown on all sides. Remove to a plate.

Add 2 cups of water to the skillet and stir.

Bring to a boil then reduce to a simmer.

Add the rouladen back to the skillet. Cover and continue simmering for 1 1/2 hours.

Mix together 2 tablespoons of water and the cornstarch until smooth.

Remove rouladen.

Whisk in the cornstarch mixture until thickened.

Whisk in the sour cream until smooth.

Return the rouladen to the pan. Carefully remove the toothpicks, coat with the gravy and serve.

Place potatoes in a large pot of boiling salted water.

Cook until tender, about 30 minutes.

Remove from water and let cool completely then refrigerate overnight.

Rice or mash the potatoes and transfer to a large bowl.

Add 1 cup of the flour, a pinch or two of salt and the eggs.

Mix well and press to form 2" balls. If the potatoes don't hold together add a bit more flour.

Place 2-3 croutons in the middle of the potato balls and lower into a pot of simmering, salted water. Simmer for 20 minutes.

Carefully remove from water using a slotted spoon and serve immediately.