Thinly slice the beef and onion.
Add oil to a pan and stir-fry the beef.
Add soy sauce, sugar, and minced garlic to the beef and continue to stir-fry.
Add the onion and cook together.
Put rice in a bowl and top it with the stir-fried beef.
Drizzle with mayonnaise.
Finish with chopped scallions and roasted seaweed flakes.