How to Make It
In a large saucepan, combine the cider, broth, kombu and 2 cups of water. Bring just to a boil, then remove from the heat. Let steep for 40 minutes. Discard the kombu and transfer the cider broth to a bowl.
Wipe out the saucepan and melt the butter in it. Add the onions, season with salt and cook over moderate heat, stirring occasionally, until golden, about 20 minutes. Add the ham and cook for 3 minutes. Stir in the barley, soy sauce and cider broth and bring to a boil. Cover and cook over low heat, stirring occasionally, until the barley is porridge-like, about 1 hour. Season with salt.
Spoon the porridge into bowls and top with the eggs. Garnish with scallions; serve.
Kombu is edible kelp. It's available at natural food stores and Asian markets.