Put the millet with the water and half a teaspoon of salt in a saucepan, bring to the boil and let it soak for about half an hour. Add a little more water if necessary.
In the meantime, chop the walnuts and cut the onion and sauté in a little oil until translucent.
As soon as the millet has absorbed the water and is soft, mix all the ingredients together. Season with sage or, if necessary, with other herbs and salt and pepper to taste.
Shape into meatballs and fry until golden brown on both sides.