Enoki Beef Rolls

Make the seasoned broth:
Mix together all of the ingredients for broth until the dashi powder dissolves. Set aside until needed.
Assemble the enoki beef rolls:
Trim off the ends of the enoki mushrooms, about 1 to 2 inches, and separate the mushrooms into small bundles, no bigger than about ¼ inch. Wrap each bundle of enoki mushrooms with a sheet of the thinly sliced beef. Repeat with all beef and enoki mushrooms.
Cook:
In a large skillet or saute pan over medium heat, add the oil. Once the pan is hot, add the sliced onion and saute until the onion softens and turn translucent.
Arrange the prepared enoki beef rolls around the pan in as even of a layer as possible on top of the sautéed onions. If you need to lower the heat while doing this, it's totally okay.
Next, pour the prepared seasoned broth around the pan, crack some black pepper on top of the enoki beef rolls (optional), cover with a lid, and bring it to a boil over medium to medium high heat. Once the broth comes to a boil, reduce the heat to keep it at a simmer and cook for about 2 to 3 minutes until the beef is just cooked through. At this point, the beef should no longer be red or pink.
Optional:
Once the beef is cooked, pour the beaten egg around the pan. Cover with the lid again and let the broth come back to a simmer. Simmer until the eggs are cooked, about 30 seconds to 1 minute.
Finish:
Uncover and garnish with sliced green onions and sesame seeds. Enjoy while hot with rice!