Remove all visible fat from the beef, wrap in plastic wrap, and freeze for about 2 hours until almost solid.

Slice the partially frozen beef with the grain into uniform 1/8-inch thick slices and arrange in a shallow dish.

In a saucepan, combine dry sherry, soy sauce, chicken or beef stock, rice wine vinegar, brown sugar, ginger, garlic, and black pepper. Bring to a boil, then cool completely.

Pour the cooled marinade over the beef slices, turning to coat. Marinate overnight in the refrigerator, stirring once or twice.

Preheat oven to 250°F and line a baking sheet with foil. Pat the beef slices dry with paper towels.

Arrange the slices in a single layer on a roasting rack and place in the oven. Immediately reduce the oven temperature to 150°F.

Dry the jerky for about 8 hours, or until stiff but still bendable, ensuring the oven temperature stays at or above 145°F for food safety.

Allow to cool completely, then store in an airtight container in the refrigerator.