Rouladen is not a favorite of mine - that is until I tried your recipe. The meat remained moist and tender. I used a Polish dill pickle with just the right amount of garlic, sweet onion from the garden and a Germain grainy mustard. Served as you suggested with Dumplings & Sauerkraut - Comfort food with a capital C.
Better than what I get in my favorite German restaurant! So flavorful, moist, and tender. I took a chance and used flank steak instead of sirloin and it came out great.