• ½ cup milk
• 1 cup fresh bread crumbs
• ½ cup finely chopped onion
• 1 large egg, lightly beaten
• ½ cup plus 2 tablespoons ketchup
• 2 teaspoons Worcestershire sauce
• 1 teaspoon salt
• 1 teaspoon mild paprika
• ¾ teaspoon ground cumin
• ¼ teaspoon freshly ground black pepper
• 1½ pounds lean ground beef
• 1 to 3 tablespoons olive oil
• 12 to 14 small hamburger rolls, split and lightly toasted
• 2 cups Papas Cintas (Shoestring Potatoes) or canned shoestring potatoes

Place the milk and bread crumbs in a large mixing bowl. When the crumbs have absorbed most of the milk, mix in the egg, 2 tablespoons of the ketchup, the Worcestershire sauce, salt, paprika, cumin, and pepper. Add the ground beef and stir or knead the ingredients with clean hands until well combined. Use a ¼-cup measure to divide the burger mixture into 12 to 14 portions. Press the meat into patties about ½ inch thick and 3 inches in diameter. Fry the burgers in a hot, well-oiled skillet or grill them over hot coals for 2 to 4 minutes, until cooked to desired doneness. Place a frita on the bottom portion of each roll. Top each burger with a small bunch of Papas Cintas and a dollop of the remaining ketchup. Place the lids on the fritas and serve immediately.