Step 1

Combine onion, dashi, sake, soy sauce, and sugar in a medium saucepan or saucier and bring to a simmer over medium heat. Cook, stirring occasionally, until onion is softened, about 5 minutes.

Step 2

Add beef and cook, stirring until beef is cooked through and liquid has reduced down to an intensely flavored broth, about 5 minutes. Stir in ginger and simmer for 1 minute longer. Adjust seasoning with salt and sugar to taste.

Step 3

Divide rice between 2 to 3 bowls and top with beef and sauce mixture. Garnish each bowl with a poached egg (if using), sliced scallions, beni-shoga, and togarashi. Serve immediately.