Finely chop the tofu and onion.
Mix the ground beef with tofu, onion, egg, breadcrumbs, minced garlic, soy sauce, and pepper.
Shape the mixture into round, flat patties.
Heat oil in a pan and cook the patties until golden brown on both sides.
Prepare bulgogi sauce (soy sauce, sugar, sesame oil, minced garlic, sesame seeds, pepper, water), pour it over the patties, and simmer.