Combine the Japanese Sweet Sauce ingredients into a small bowl and mix together.
Peel and julienne the ginger bulb. Mince the garlic cloves. Cut the stems off the asparagus and cut into three. Peel the lotus root, cut in half and slice into 5mm slices.
In a large wok, heat the sesame oil and add the lotus root. Fry for 3-4 minutes until both sides start to get golden brown.
Add the ginger, garlic and asparagus, and fry 1-2 minutes until they start to get crispy.
Add the thinly sliced beef and the sweet sauce to the pan, mix everything together and fry until the beef is cooked through, about a minute or two. Try not to overcook or the beef will get tough.
Sprinkle the sesame seeds over everything.
Notes
*Dashi powder is granulated Japanese Fish stock. If you can't find some granule type, you can make your own by boiling some bonito flakes in some water for 10-15 minutes and straining the flakes after. The leftover water is dashi. You can also substitute for any type of chicken/beef/vegetable bouillon you have on hand.**Since I live in Japan, thinly sliced meat is readily available at any stores, but for those in other countries, ask your local butcher shop to slice some or go into the Chinese Hot Pot section in the freezer section. They usually have some there.