Stir the masa harina and hot water in a large bowl. Add the beef, pork, onion, garlic, oregano, salt and black pepper and mix thoroughly. Shape the beef mixture firmly into 16 (1 1/2-inch) meatballs.

Heat the oil in a 12-inch nonstick skillet over medium-high heat. Add the meatballs and cook for 10 minutes or until well browned and cooked through. Remove the meatballs from the skillet.

Stir the soup and water in the skillet and heat to a boil. Return the meatballs to the skillet and stir to coat. Reduce the heat to medium-low. Cook for 5 minutes or until the meatballs are hot, stirring occasionally.