Step 1
Preheat oven to 325 degrees F (165 degrees C).
Step 2
Heat 1 tablespoon butter over medium heat in a large frying pan; stir in 1 onion and saute until softened about 5 minutes. Set aside to cool slightly.
Step 3
Stir pork ground beef bread crumbs salt and pepper together in a bowl; stir in onion. Pour beaten eggs over meat mixture; mix with your hands until well combined.
Step 4
Spread about 1 1/2 tablespoons of meat mixture onto each beef slice; top each with one pickle quarter. Roll beef slices around filling; secure each roll with a toothpick.
Step 5
Heat 2 tablespoons butter in the same frying pan; place rolls into pan and brown on all sides about 10 minutes. Remove rolls; place in a single layer in a roasting pan.
Step 6
Heat remaining 2 tablespoons butter in the same frying pan over medium heat; cook and stir remaining onion celery carrots and garlic until vegetables are soft about 10 minutes. Stir in 3 cups water tomato paste sherry bouillon granules and bay leaf; bring to a boil. Pour sauce over rolls in roasting pan.
Step 7
Bake in the preheated oven until tender about 3 hours; remove from oven to turn rolls over halfway through the cooking time.
Step 8
Remove rolls to a heated platter. Place roasting pan with sauce on the stove; bring to a boil. Whisk cornstarch and 1/3 cup water together in a cup; slowly whisk cornstarch mixture into sauce until thickened about 5 minutes. Drizzle some sauce over the rouladen; serve the remaining sauce in a gravy boat.