Preheat a pan over medium heat. Season the steak with the SPG.
Melt the butter in the pan. Put the seasoned steak into the pan and brown on both sides. Cook to your desired doneness level. We prefer medium-rare. Remove from the heat and set aside before slicing.
Combine the soup base, seasonings, and bok choy in a pot. Bring up to a simmer.
While that is simmering, preheat the oil in a small skillet and brown the shiitake mushrooms. Once they are browned on both sides, add to the soup base.
Add the fresh udon noodles to the pot and let simmer for a few minutes (according to package directions.)
Top with your furikake, jammy egg, and chopped green onion.
Notes
Follow the directions on your particular brand/type of soup base for best results. They have varying strengths. Use as much as is called for according to the package.