This is a kind of rice bowl dishes in which tonkatsu and slices of onion cooked with egg in the warishita stock (the basic seasoning in Japanese cuisine prepared with soup stock, sugar, and soy sauce) are served on rice.
丼飯の上にタマネギを割下で煮てトンカツを入れ鶏卵でとじたものをのせた料理で丼物の一種。