Mix the chicken fat or vegetable oil with the eggs, salt, nutmeg, ginger, matzo meal and parsley together in a medium bowl. Cover and refrigerate for a few hours or overnight.
Bring 3 quarts water to a boil in a large pot. Take the matzo mix out of the refrigerator and, after dipping your hands into a bowl of cold water, gently form balls the size of large walnuts. Add the salt to the water and drop in the balls.
Simmer slowly, covered, for about 20 minutes, remove from water with a slotted spoon, and add to the soup.