Trim the excess fat and silver skin from the steak and cut into strips about 1/2-inch wide and 2 to 3 inches long.
Whisk together the buttermilk, Worcestershire, 2 teaspoons of the salt and 1 teaspoon each of the black pepper, granulated garlic, dry mustard and paprika in a bowl. Add the steak strips to the buttermilk mixture and refrigerate for 2 hours.
Heat 3 inches of oil in a Dutch oven to 350 degrees F.
Whisk together the flour, the remaining 2 teaspoons salt and the remaining 1 teaspoon each of the black pepper, granulated garlic, dry mustard and paprika in a shallow dish.
Strain the meat, reserving the buttermilk mixture. In batches, dredge the strips into the seasoned flour, then back into the buttermilk mixture, and back again into the seasoned flour.
Dip the double-dredged strips carefully into the hot oil. You will need to fry them in batches to avoid overcrowding. When the strips are golden brown and crisp, about 4 minutes, remove them with a slotted spoon onto a paper-towel-lined plate.
Serve the steak fingers immediately with french fries and cocktail or BBQ sauce.