Pour water in a cooking pot and let boil.
Put-in the halved onion, leeks, 1/2 tablespoon salt and whole peppercorns.
Add-in the round steak and allow the water to re-boil. Simmer for 45 to 60 minutes or until the beef is tender.
Remove the beef from the cooking pot and let the meat rest for 15 minutes. Slice thinly, and set aside.
Make the Criolla Sauce by combining all the ingredients in a mixing bowl.
Arrange the meat and the sauce in a serving plate by alternately layering the meat and the sauce.
Refrigerate for at least 4 hours.
Serve. Share and Enjoy!