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Green Bean and Mushroom Doria topped with fried onions and parsley.

Mushroom Doria (Mushroom Rice Casserole)

Doria, a staple of Japanese home-cooking, is a marvelously comforting rice casserole covered in a bubbling layer of creamy béchamel sauce topped with a crisp sheet of browned cheese. For this recipe, I've mashed up Doria with Green Bean Casserole to come up with an easy make-ahead dish that's perfect for an autumn potluck or holiday feast.
Course Side Dish
Cuisine Japanese
Keyword amatrice, casserole, make-ahead, party food, potluck
Level Beginner
Main Ingredient Rice
Diet Low Sugar, Vegetarian
Prep Time 10 minutes
Cook Time 30 minutes
Total Time 40 minutes
Servings 4 servings
Calories 394kcal


for casserole

  • 1 teaspoon cultured unsalted butter
  • 350 grams cooked rice (1 rice cooker cup)
  • 100 grams Gruyere cheese (or other melting cheese, grated)
  • Fried onions (for garnish)

for filling

  • 180 grams green beans
  • 1 tablespoon cultured unsalted butter
  • 100 grams onions
  • 120 grams button mushrooms
  • 100 grams shimeji mushrooms (beech mushrooms)
  • 1 teaspoon salt

for bechamél

  • 1 tablespoon cultured unsalted butter
  • 25 grams flour (about 2 ½ tablespoons)
  • 1 ½ cups milk


  • Butter a 10-inch casserole dish using about a teaspoon of butter. Move the oven rack to the middle position and preheat the oven to 500 degrees F (260 C).
    Buttering casserole dish for making Doria.
  • Bring a large pot of salted water to a rolling boil and the whole green beans.
    Boiling green beans for Doria.
  • Blanch the beans by bringing the water back up to a full. Drain the beans and rinse them under cold water to chill them enough to handle.
    Chilled blanched green beans.
  • Trim the stem ends off of the beans and chop them up into 1.5-inch lengths.
    Chopped blanched green beans on cutting board.
  • Melt 1 tablespoon of butter in a frying pan over medium heat and sauté the onions, button mushrooms, shimeji mushrooms, and salt until the mushrooms are starting to caramelize (about 6-7 minutes).
    Sauteeing mix of Button and Shimeji Mushrooms.
  • Transfer the mushrooms to a bowl and add the remaining tablespoon of butter to the pan along with the flour. Cook the roux until there are no lumps of flour, but don't let it brown.
    Cooking flour and butter roux in frying pan.
  • Turn down the heat and pour the milk in at once. Stir the mixture vigorously until there are no lumps of roux remaining.
    Making white béchamel sauce.
  • Turn up the heat to medium and bring the béchamel to a boil to thicken. Add the sauteed mushrooms as well as the green beans to the pan, and stir to distribute evenly.
    Green beans and sautéed mushrooms in béchamel sauce.
  • To assemble the Doria, spread an even layer of rice along the bottom of the buttered casserole dish.
    Layer of rice in buttered casserole dish.
  • Top with the mushroom and green bean béchamel.
    Green bean and mushroom béchamel layered over rice to make Doria.
  • Cover with an even layer of shredded cheese.
    Assembled Doria with cheese on top.
  • Put the Doria in the oven and bake until the sauce is bubbly and the cheese has browned on top, about 15-20 minutes.
    Doria baking in the oven.



Calories: 394kcal | Carbohydrates: 42g | Protein: 16g | Fat: 18g | Saturated Fat: 11g | Cholesterol: 54mg | Sodium: 714mg | Potassium: 475mg | Fiber: 3g | Sugar: 8g | Vitamin A: 902IU | Vitamin C: 8mg | Calcium: 387mg | Iron: 1mg