Prepare the ingredients: cut potatoes and onions into large chunks, carrots into smaller pieces, and beef into bite-sized pieces. Drain excess blood from the beef using paper towels.

In a wok, combine water, soy sauce, corn syrup, and mirin. Adjust water quantity if you prefer a lighter taste.

Add potatoes and beef to the wok and bring to a boil over high heat.

Skim off any foam that rises to the surface, reduce heat to low, cover, and simmer for about 20 minutes.

After 20 minutes, check the seasoning and adjust if necessary. Add more water if the flavor is too strong.