Doria is a Japanese casserole dish made with rice, creamy white sauce, and cheese. It’s a popular Western-influenced dish (Yoshoku) often served at Kissaten styled coffee shops in Japan. In this recipe, instead of serving in individual gratin dishes, doria is made in a deep pie dish that is ideal for family-style serving. After sauteing the chicken, mushrooms, and onion, we use the same frying-pan to make it simple (and less pots to clean!) Ketchup flavored rice goes really well with the creamy white sauce, but if you would like to skip adding the ketchup, that is totally fine, too. Doria is a hearty, warm, and comforting dish that is perfect for a winter dinner. Enjoy!