In a bowl, combine the ground sirloin, bread crumbs, milk, onion powder, garlic salt and pepper. Mix well. Separate the mixture into 12 large meatballs. For each meatball, slightly flatten the meat in the palm of your hand. Place 1 cube of cheese in the center of the flattened meatball and then form the meat around the cheese cube. Make sure the cheese is completely covered with the meat mixture.
Place the flour in a small bowl. Roll each meatball in the flour to lightly coat the outside. Heat the oil in a large skillet or saucepan over medium heat. Add the meatballs and brown them on all sides.
While the meatballs are browning, combine all of the ingredients for the pizza sauce in a bowl and stir to mix in the spices.
If there is excess fat in the pan after the meatballs have browned, drain the fat. (We used lean meat and didn't have any fat in the bottom of the pan.) Add the pizza sauce to the meatballs and heat it until boiling. Reduce the heat to medium low and cover the pan. Simmer the meatballs for 20-25 minutes. The time depends on how brown they got initially and how big the meatballs are, so be sure to check inside the meatballs to check if they are browned through.
Serve over rice, pasta or on a hoagie bun.
Notes
This recipe can easily be doubled. This is a good crockpot meal, too. After the meatballs are cooked, place them in a slow cooker and cover them with sauce. Set the temperature to low.