What happens next?

How to make gyudon
Slice the beef and vegetables.
Use a sharp knife to shave the beef into very thin slices. Cut the onion and shiitake mushrooms into moderately thin slices, as well.

pick from the following.
+ Heat oil in a skillet over medium heat. Set aside for about a minute so the pot can drain completely.
+ To save yourself time and effort, ask the butcher to slice the beef very thinly before packaging it. If the butcher does not slice the beef, freeze it for 1 hour before slicing it yourself.
+ Finally, cut the mushrooms into quarters and the beef. Mash the ingredients together into a nice pea-sized bowl until it's smooth and light.
+ You can also use a meat tenderizer instead, that's gentler on the meat and also less fancy. Don't use the steak or pound of beef in this recipe as the meat will soften more easily than the tenderizer.
To save yourself time and effort, ask the butcher to slice the beef very thinly before packaging it. If the butcher does not slice the beef, freeze it for 1 hour before slicing it yourself.