My family loves squash soup.
At home, I make a lot of kabocha no nimono, a classic Japanese dish featuring chunky, skin-on dice of kabocha squash simmered in dashi broth seasoned with mirin and sake.
As the squash softens, it absorbs the broth, giving each bite a powerful but balanced mix of umami, sweetness and saltiness. I often take the leftovers and blend them into a soup that I thin out with more dashi. It’s a family favorite, and the one-pot, no-peeling simplicity means that it’s a dish I can easily cook on a weeknight.
We also enjoy Western-style roasted squash soups, which can get a similar sweetness and savoriness when the squash is roasted slowly enough to set off the browning reactions that deepen its flavor and the caramelization that adds complexity to its natural sugars. To make a roasted squash soup with a hard squash like butternut or Hubbard, I’d typically halve the squash, scoop out the seeds, and then roast it low and slow until the flesh is completely tender before carefully peeling and discarding the skins, using a spoon to scrape off as much flesh as possible. It’s a more tedious process, making it a once-a-month recipe.
These days, with two hungry kids in the kitchen, trimming minutes or seconds off my prep and cleaning time is a top priority. If I could skip the drawn-out peeling and scraping steps by using a more thin-skinned squash like kabocha or kuri, a roasted squash soup could potentially become a weeknight staple.
So I tried it.
I rubbed a split kabocha squash with oil, seasoned it with salt and pepper, and roasted it on a sheet pan at 325 degrees until it became sweet, tender and lightly caramelized in spots. I then scraped the squash, skin and all, directly into a Dutch oven in which I’d sweated aromatics — onions, carrots, ginger and apples — in olive oil, then added vegetable stock and blended everything into a smooth purée. It was split-pea green from the kabocha skins, but it was delicious. A subsequent batch I made with red kuri squash was equally tasty with a bright orange color.
My next thought was to take advantage of the sheet pan in the oven to eliminate having to sauté the aromatics on the stovetop. So I made a batch of soup in which I tossed the thin-sliced aromatics in olive oil, then piled them on top of the split squash before roasting everything together. As the aromatics roasted, they took on a range of flavors: from the frizzled, darkened, caramelized bits of onion and apple at the edges of the pan to the milder aroma of the sweated ginger and carrots in the center of the piles.
As I was scraping the contents of the sheet pan into my Dutch oven, I remembered a tip I had read in Sam Sifton’s “No-Recipe Recipes.” The Times’s former food editor, he suggests roasting a whole head of cauliflower in the same Dutch oven that the soup will be puréed and finished in. It turns out that the technique is perfect for squash. I tossed my prepared squash and aromatics with olive oil directly into a Dutch oven, which I then placed in a preheated oven to roast. (To properly caramelize bits of the squash and aromatics protected by the walls of the Dutch oven, I needed to increase the oven temperature to 375 degrees.)
Once the vegetables were softened, I deglazed the pan with stock, scraping up the browned bits from the bottom and sides, then puréed everything with a hand blender, adding a small splash of maple syrup to complement the squash’s sweetness and a squeeze of lemon juice for brightness. The flavor was outstanding. It was all cooked and served in a single pot, and it took only a few minutes of active time, placing it right up there with kabocha no nimono as far as simple weeknight dishes go.
There are some recipes I test that my family gets sick of within a few days, but this was not one of them. Like I said, we really love squash soup.