Prepare the pork broth by blanching the pork bones in boiling water for 10 minutes, then rinse under cold water to remove impurities.
In a large pot, combine the cleaned pork bones with enough water to cover. Add 2 cloves of garlic and ginger. Bring to a boil, then simmer for 8-12 hours until the broth is rich and milky.
Marinate the pork belly with soy sauce, mirin, 2 cloves of minced garlic, and a pinch of black pepper. Allow to marinate for at least 1 hour.
Preheat the oven to 180°C (350°F). Place the marinated pork belly on a baking tray and roast for 1 hour until the skin is crispy and the meat is tender.
Cook the eggs in boiling water for 6 minutes, then transfer to an ice bath. Once cool, peel and set aside.
Cook the noodles according to package instructions. Divide the noodles among bowls.
Slice the roasted pork belly and arrange on top of the noodles. Pour the hot broth over, ensuring it covers the noodles and pork.
Garnish each bowl with a halved boiled egg, finely sliced spring onions, a sheet of nori, and a drizzle of sesame oil. Season with salt and pepper as desired.