Part 1

1. Start heating a large pot of water (enough to submerge the pork). When it reaches boiling, turn down to a simmer.
2. Heat a frying pan on medium/medium-high and sear the pork belly on all sides.
3. Once seared, transfer the pork to a chopping board and let it cool for a few minutes. When it's cool enough to touch, cut it into chunks.
4. Place the chunks in the pot of water and allow to simmer for 10 minutes.
5. After 10 minutes have passed, pour the pork into a colander and run it under cold water to clean it.
6. Fill the pot up with enough fresh water to cover the pork and bring to a boil once more.
7. While you're waiting for the water to heat up, cut the ginger into slices (leave the skin on) and break the Welsh onions into halves or thirds so that they fit inside the pot. 
8. Once the water is boiling, turn it down to a simmer and add the pork, Welsh onion and fresh ginger.
9. Simmer for one hour on a low heat.

Part 2

1. Once an hour has passed, turn off the heat and transfer 500ml (2 cups) of the pork broth to a new, smaller pot.
2. Add 100ml beer, 1 tbsp honey, 2 tbsp light brown sugar and 100ml soy sauce and turn on the heat. Once it's boiling, turn the heat down to simmer and add the pork.
3. Place a drop lid on top of the pork and simmer on low for 30 minutes.
4. When 30 minutes are up, turn off the heat and leave to cool for at least one hour. You can add soft boiled eggs at this point. (Once cooled you can keep it in the fridge.)
5. Heat on medium for 30 minutes before serving. Remove the eggs after 5-10 minutes to prevent overcooking.
6. If you want to garnish with "shiraganegi", cut the white part of a Welsh onion into thin strips and soak in cold water with a pinch of salt until serving.
7. Dish up and serve with Japanese mustard.
8. Enjoy!