Boil the potatoes, peel the skins, and mash with a fork. If you mash them nicely, they will be nice and smooth.
Place Step 1 into a gratin dish. Add the white sauce and milk, and mix. Season well with salt and pepper.
Spread the meat sauce on top. The small one in the picture is for a bento.
Sprinkle with cheese.
Bake in the oven for about 10 minutes at 230℃ until browned.
It's so creamy.