Form the Meatballs
Divide the meat mixture into 5 equal portions. Take one portion and flatten it in the palm of your hand. Place a hard-boiled egg in the center and wrap the meat mixture around the egg, forming a large meatball. Make sure the egg is completely encased in the meat mixture. Repeat this process for the remaining portions and eggs, ensuring uniformity in size for even cooking.
Prepare the Baking Dish
Place the thinly sliced onions in the bottom of a baking dish. This not only adds flavor to the meatballs but also prevents them from sticking to the dish, ensuring an easy and clean presentation.