Cut the potatoes into bite-sized pieces and soak in water for 5 minutes. Drain the water. Cut the carrot into irregular bite-sized pieces. Slice the onion into 1.5cm widths. Remove the strings from the snow peas and cut them diagonally in half.

Heat salad oil in a frying pan over medium heat. Add the beef and stir-fry until the color changes. Add potatoes, carrots, and onions, and stir-fry until coated with oil.

Add the seasoning ingredients (sake, mirin, sugar, water) to the pan and bring to a boil. Skim off any foam, cover with a lid, and simmer over medium-low heat for 10 minutes.