In medium pot over medium heat, combine water, dashi granules, tamari, mirin, and honey.
Cut pork belly strips into bite-sized pieces, about 2-3 inches in length.
Add pork to the pot, stirring to separate meat slices. Bring to a gentle boil.
Cover pot with lid, leaving a slight gap and reduce heat to a low. Simmer for at least 30 minutes (45 minutes is best).
Remove lid and add onions. Mix well and simmer uncovered for another 15 minutes.
Serve over hot rice, spooning some of the braising liquid over the meat.
Garnish with chopped green onions, Shichimi Togarashi (Japanese pepper mix) and pickled ginger, if desired.
Notes
This the brand of dashi granules I use and what they look like. Compared to some other brands, I find this one to have the simplest list of ingredients:
Alternatively, look for dashi bags, which are like tea bags that you soak in water to get the dashi broth.