Recipe sourced from

Makes 8 servings (Prep time: 30 minutes Cooking time: 45 minutes)


  • 1 Tbsp unsalted butter (to grease the baking dishes)
  • 1 ½ lb kabocha (squash/pumpkin) (½ kabocha)
  • 1 clove garlic
  • ½ onion (~4 oz)
  • 9.5 oz king oyster mushrooms (1 package)
  • 3.5 oz shimeji mushrooms (1 package)
  • 1 ½ Tbsp extra-virgin olive oil
  • 1 ½ Tbsp miso
  • 1 cup water
  • Kosher/sea salt (use half for table salt)
  • Freshly ground black pepper
  • ½ cup Gruyere cheese (freshly grated)
  • ¼ cup (4 Tbsp) panko (Japanese breadcrumbs)
  • Chives or parsley, minced (for garnish)

For Macaroni

  • 1 ½ cups uncooked elbow macaroni (6 oz; makes 3 cups cooked macaroni)
  • 2 Tbsp kosher/sea salt (use half for table salt)

For Bechamel Sauce (White Sauce)

  • 4 Tbsp unsalted butter
  • ½ cup all-purpose flour (plain flour)
  • 3 ⅓ cup whole milk (warm)
  • Kosher/sea salt (use half for table salt), to taste
  • ⅛ tsp white pepper powder, to taste (black pepper is okay)
  • ¼ tsp freshly grated nutmeg, to taste (optional)


  • Microwave the kabocha for 2 minutes and remove seeds and pith from the kabocha.  To learn more about how to cut kaboha squash, click here.
  • Cut into wedges and remove the skin.
  • Cut into small chunks, about 1 inch cubes.
  • Thinly slice the onion and garlic.
  • Discard the bottom of the shimeji mushrooms. Separate shimeji mushrooms into small pieces with hands.
  • Cut the oyster mushrooms into 2-inch pieces and slice thinly.

To Make White Sauce*

  • In a large saucepan, melt 4 Tbsp butter over low heat. Once the butter is completely melted, add the flour and mix well until blended. Cook the flour, stirring constantly, without browning, for 1-2 minutes.
  • Gradually add in the warm milk (½ cup at a time), stirring constantly, until the sauce is completely smooth without any lumps.
  • Season with a pinch of kosher salt, white pepper (or freshly ground black pepper), and nutmeg.
  • Cook the white sauce, stirring constantly until the sauce has thickened, about 10-15 minutes. It should be a thick creamy sauce. Taste the sauce one more time and adjust the seasonings to make sure it’s not bland. Set aside. Tip: If you end up with leftover white sauce, it can be stored in an airtight container in the refrigerator for up to 3-4 days.

To Cook Kabocha

  • In a large frying pan, heat 1 ½ Tbsp extra virgin olive oil. Add the garlic and onion and sauté until the onion is coated with oil.
  • Add the oyster and shimeji mushrooms and cook for 2-3 minutes.
  • Once the mushrooms are tender, add the miso and mix well together.
  • Add the kabocha and 1 cup water for steaming. Close the lid and cook kabocha on medium-low heat until it’s tender, about 10 minutes.

To Cook Pasta (if you add macaroni)

  • Meanwhile, in a large pot of boiling water, add 2 Tbsp kosher salt and cook macaroni according to the package instruction, but cook 1 min less than the instruction as it’ll cook further in the frying pan. Drain well and set aside.
  • If you’re using a broiler, preheat the broiler for 5 minutes. If you don’t have a broil setting in your oven, preheat the oven to 500ºF. Adjust the rack so the food is about 4-6 inches from the heat source.

To Assemble

  • Insert the wooden skewer to see if it goes through kabocha. If it does, add the white sauce and mix all together.
  • Taste the sauce and season with salt and black pepper if necessary.
  • Add the cooked macaroni and mix well.
  • Grease the inside of your two 8” x 8” baking dishes rubbing with a stick of butter. You can also melt the butter and use a brush to grease the dishes.  Transfer the mixture to the buttered baking dish(es).
  • Grate the Gruyere cheese on top and sprinkle some panko.
  • Place the baking dishes in the oven (broiler or 500 ºF) for 3 to 4 minutes until the top is nicely golden brown and bubbling around the edges. If the dishes are not browning evenly, rotate them around. Remove from the oven and let the gratin stand for 5 minutes, then garnish with chives and serve.

To Store

  • You can keep the leftovers in an airtight container and store in the refrigerator for up to 3 days and in the freezer for a month.

*To make the perfect bechamel sauce

1. Patiently cook the roux – You want to make sure that the flour in the roux is cooked well, which should be about 5-7 minutes until the roux turns into light golden color. If you don’t cook the roux long enough, the white sauce will have a raw floury taste.

2. Always use warm milk – Heat up the milk until warm to the touch. This extra step helps as it takes less time to heat up and thicken the sauce and you don’t have to stir constantly for a longer time.

3. Gradually add in the milk – Never pour the milk all at once! You want to gradually add in the warm milk, about ¼ cup at a time. Make sure the milk and the roux are well blended without any lumps before adding the next batch. Continue cooking while stirring constantly because the thick white sauce easily burns. Wait for the point when the white sauce changes the texture to become very smooth, thick, and creamy.