Measure out the soy sauce, mirin, sake, dashi and sugar in 2 cup measuring cup
Add sliced onions, and sliced beef to a large saute pan. Pour liquid mixture and cover with lid. Turn stove on to medium heat.
When the meat is cooked, skim off the scum and fat from the broth with a fine-mesh skimmer. Turn down the heat to simmer and continue cooking, covered, for 3–4 minutes.
Cut green onion/scallion into thin slices.
Next, crack and beat 4 large eggs in a small bowl.
Slowly drizzle a thin stream of the beaten eggs over the simmering beef, placing your cooking chopsticks at the edge of the bowl with the eggs to control the flow. Do not mix the egg with the beef. Sprinkle the green onions on top and cook covered on medium-low heat until the egg is done to your liking (but don‘t overcook it). Usually, rice bowls with eggs in Japan are served while the egg is almost set but still runny. Remove from the heat.
You can keep the leftovers in an airtight container and store in the refrigerator for up to 3 days and in the freezer for a month.
