Cut the new potatoes into bite-sized pieces with the skin on, soak them in water, and drain. Place them in a microwave-safe container, cover loosely with plastic wrap, and microwave at 600W for about 5 minutes until a skewer can easily pierce through. Drain any excess water.

Julienne the ginger and cut the green beans diagonally into thirds.

Heat salad oil in a frying pan over medium-low heat, add ginger and pork, and stir-fry until the pork changes color.

Add the microwaved potatoes and stir-fry until they are coated with oil.

Add the simmering sauce ingredients (water, sake, mirin, sugar, soy sauce) and bring to a boil. Cover with a lid and simmer on low heat for 5–6 minutes. Add the green beans in the last minute of simmering.