Cook the rice according to the recipe on the package.
Cut the meat into thin slices. Cut the onion into feathers, and grate the ginger on a fine grater.
Pour water into a saucepan, add dashi and bring to a boil. Throw in the onions and cook for a few minutes until they soften. Then add soy sauce, sake and sugar. Stir and add the beef. Cook covered for about 10 minutes. Add grated ginger and cook for another minute.
To prepare eggs extra soft (onsen tamago), boil about a liter of water in a saucepan. Then remove it from the heat. Add 1 tbsp of potato flour diluted in a little cold water. Stir thoroughly. Then carefully put 2 eggs, cover and set aside for 8 minutes. After this time, gently notch the eggshell and break the eggs into a bowl.
Place rice, beef, and onsen tamago into the bowl and sprinkle the whole thing with chives.
You can serve with your favorite vegetables, such as cucumber or radish.