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Tender chunks of sweet kabocha, umami mushrooms, and macaroni in a creamy béchamel sauce, topped off with panko breadcrumbs and baked until crispy golden. Kabocha Gratin with a Japanese twist is the ultra comfort food in cold weather months.
When there is a chill in the air, it is time to turn to warm casserole dishes. Now it might surprise you that the Japanese also eat homey western cuisine. Yes, we love our cozy dishes, but very often we enjoy them with Japanese flavors. Among the myriad western-style Japanese food or yoshoku out there, the two popular casserole dishes are Gratin (グラタン) and Doria (ドリア), a Japanese invention of rice gratin.
Today I’m going to share our fall favorite gratin, Kabocha Gratin (カボチャグラタン). You can use rice or pasta for your choice of carb. I used macaroni, so think fancy Japanese style mac and cheese. Rich and indulgent, this vegetarian-friendly recipe would make a really nice side dish or a complete meal on its own.
Watch How To Make Kabocha Gratin
The Star Ingredient – Kabocha
The outstanding texture and sweetness of Kabocha are what make this gratin shine. Not only does it add so much more flavor and heartiness to the entire dish, but the bright vivid orange flesh also gives the gratin an extra holiday touch.
Since kabocha is loaded with plenty of nutrients, you get extra goodness out of this comfort dish. If you prefer less carb, just adjust the ratio of kabocha and macaroni to your liking.
Making Perfect Bechamel Sauce (White Sauce)
Don’t get taken aback when you hear “bechamel sauce”. It may sound fancy to the ears, but in fact, it is a simple sauce to make. In Japan, we just call it “white sauce” (ホワイトソース). The cheesy creamy sauce is often used to make soups and stews like my Clam Chowder, and Japanese White Stew (ホワイトシチュー) recipes.
To make a good white sauce, you need to remember three important points.
1. Patiently cook the roux
First of all, the roux is made by equal parts of fat (butter, coconut oil, ghee, etc) and flour by volume. You may find that many recipes adjust the amount like how I did in this recipe. The butter and flour swell as they cook and will thicken sauces.
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
I highly recommend heating 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. It’s MUCH harder to dissolve clumps of flour in a thin sauce.
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.
A Japanese Twist – Miso!
I like to sneak in a Japanese condiment in western-style dishes. It’s my “secret ingredient”. In Japanese, we say Kakushi Aji as a special touch to give the dish a subtle Japanese flavor.
The recipe is delicious even without miso in it, but if you have a tub of miso in your fridge waiting to get used, this is your chance! Each miso has a different salt level, so you want to adjust the amount of miso flavoring the dish. The white sauce is pretty mild in taste, so you can season the kabocha and mushroom mixture pretty well, without having to worry it gets too salty when the whole dish comes together.
Variation of Kabocha Gratin
If you wish to add in some meat to bulk up the casserole, there is no reason not to do so. Some shredded chicken or leftover turkey would work well in the dish. I love the addition of bacon. You probably have heard me repeating this – bacon and kabocha are an excellent match!
You can keep the gratin simple with just kabocha or kabocha and macaroni, but I like throwing in some king oyster mushrooms and shimeji mushrooms. The meaty mushrooms lend the right amount of umami to an already amazing creamy kabocha gratin.
I love taking the kabocha gratin out of the oven with its golden baked cheese still bubbling around the edges. As it cools on the stove, garnish with some chives. You will have a delicious casserole dish ready for dinner, or at your next holiday party!
Japanese Ingredient Substitution: If you want to look for substitutes for Japanese condiments and ingredients, click here.
- 1 Tbsp unsalted butter (to grease the baking dishes)
- 1 ½ lb kabocha (squash/pumpkin) (½ kabocha)
- 1 clove garlic
- ½ onion (4 oz, 114 g)
- 9.5 oz king oyster mushrooms (eringi) (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 (I use Diamond Crystal; Use half for table salt)
- freshly ground black pepper
- ½ cup Gruyere cheese (freshly grated)
- ¼ cup panko (Japanese breadcrumbs) (4 Tbsp)
- 1 ½ cups uncooked elbow macaroni (6 oz; makes 3 cups cooked macaroni)
- 2 Tbsp kosher/sea salt (I use Diamond Crystal; Use half for table salt)
- 4 Tbsp unsalted butter
- ½ cup all-purpose flour (plain flour)
- 3 ⅓ cup whole milk (warm)
- kosher/sea salt (I use Diamond Crystal; 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)
- chives or parsley (minced)
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 (2.5 cm) 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 (5 cm) pieces and slice thinly.
In a large saucepan, melt 4 Tbsp (56 g) 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.
- 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 (240 ml) water for steaming. Close the lid and cook kabocha on medium-low heat until it’s tender, about 10 minutes.
- 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 (260ºC). Adjust the rack so the food is about 4-6 inches from the heat source.
- 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” (20 x 20 cm) baking dishes rubbing with a stick of butter (I use one of 8” x 8” baking dish and 4 individual gratin dishes). 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/250 ºC) 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.
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.