Step 1

Heat 2 tablespoons oil in a large skillet over medium high heat, and cook the sliced onions for about 10 minutes, stirring often.

Step 2

Add the beef and sugar, and cook until the beef is slightly browned. Add the mirin, soy sauce, and stock. Bring to a simmer, and cook for about 10-15 minutes to reduce the stock into a thin sauce. Taste for seasoning, and add a little more soy sauce if needed.

Step 3

Meanwhile, heat another couple tablespoons of oil in a cast iron or non-stick skillet. Cook the eggs sunny-side up. You can cook them in batches if needed. The yolks should still be runny!

Step 4

When the beef is done simmering, divide the rice among 4 bowls, and top with the beef and an egg for each bowl. Garnish with chopped scallion and toasted sesame seeds, if using.