In a large stock pot or dutch oven, add chicken, quartered onions, full bulbs of garlic (slicded down the middle), sliced ginger, whole green onions, salt, black pepper, and water, and cover.
If using the meat to eat in the ramen or something else, after an hour, remove meat from bones. Return all bones and skin into broth and re-cover. It’s very important that the broth is covered the whole time it cooks, otherwise it will evaporate.
Once you’re ready to finish your ramen, in a separate pan, saute your additional grated garlic, ginger, and miso paste in sesame oil for about 5 minutes. Then strain ramen broth into that pot. (You really start to infuse flavor after an hour, but the longer the better. I usually do like 3-5 hours)
Serve immediately or keep hot until ready to serve