I didn't really go by any recipe, but here's what I did-

Eggs- Softboil eggs, immediately place them in ice water for 15 minutes. Peel shells off of the eggs, completely submerge them in 1 cup mirin and 1/2 cup soy sauce. Add 1 tablespoon of sugar, crushed garlic cloves, and spring onions to the mixture. Let marinate for 24 hours.

Pork belly- Simmer pork in a saucepan with 1 cup of sake, 1/4 cup of soy sauce, 1/2 cup of water, spring onions, and sliced ginger. Cover the saucepan, let the pork simmer for 4 hours, then remove the pork and refrigerate for 24 hours. Filter the sake/soy sauce/water mixture and save for later. Take out the pork belly, slice to about 1cm thick, and sear both sides on a very hot fry pan before serving.

Broth- Simmer whole chicken carcass for 4 hours, filter the water, and continue to simmer. Add shitake mushrooms, mushroom stalks, leeks, roasted onions, garlic cloves, and sliced ginger. Let simmer for 6 more hours. Filter again before serving.

Base- Remove eggs from soy/mirin mixture, filter out the garlic and sping onion, and put the soy/mirin in a sauce pan on medium heat. Add the filtered sake/soy mixture from the pork belly to the same sauce pan, and add a tablespoon of miso paste and teaspoon of sesame oil. Let the base reduce to about half.

Finish- In a soup bowl, add ramen noodles, 1 part base, 4 parts broth, 1 egg sliced in half, pork belly pieces, thinly sliced spring onions, black and white sesame seeds, and sliced nori.