How to make butadon – Japanese rice bowls with pork and onion – hearty, comforting and topped with an egg yolk

• Donburi are simple but hearty Japanese rice bowls that are served with all kinds of toppings, from eel to tempura
• This recipe is for butadon, which comes with thinly sliced pork belly and onions topped with an egg yolk – raw, poached or fried