Peel and grate the potato. Cook it with the rice in extra water (more than you would normally use for rice) in a pot, without oil, until the mixture is very soft and mushy. Then knead the mixture by hand or use a meat grinder.

Finely chop the onions and sauté them with the ground beef in a pan, without adding oil, until cooked through. Add the cilantro or parsley and pine nuts, then remove from heat.

Shape the rice mixture into balls about the size of your palm. Use your finger to make a hole in the center, fill with the meat mixture, and shape into an oval using your hands.