This is full-on rib-sticking stuff with 2 types of miso: a deep red miso for the marinade and for cooking, then a sweet white miso to mellow put the rich broth. It requires overnight marinating, but actually very little attention once everything is in the hot pot. Return 2 hours later for a rich reward.
If you have any broth left over, throwing some noodles into it the next day for a rich topknots-style ramen, so you can enjoy at least 2 meals out of this.
In a small mixing bowl, combine the miso, sake, mirin and soy sauce to create a marinate. slice the belly rashers into 5cm cubes, rub the marinade over them, cover and leave overnight in the fridge.
The next day, brown the pork belly in a hot pan without oil, reserving the marinade, until the edges of the pork begin to darken and crisp up.
In a large casserole pan, heat up the olive oil and cook the daikon and carrot for 2-3 minutes until slightly softened. Add the pork belly and all the leftover marinade, then pour in 1 litre of hot water.
Cook over a low heat for 90minutes to 2 hours until full softened and melting away. Keep checking every 30minutes with a quick stir to prevent anything sticking to the pan. In the last 5 minutes of cooking, strain the sweet white miso paste through a sieve into the hot pot.
Sprinkle with finely chopped spring onions and serve with plenty of plain steamed rice and some stir fried greens such as kale or savoy cabbage. This is such a rich wish, you really won't need much else.