I’ve had a couple tubs of Thai curry paste kicking around in my fridge since the summer. But when butternut squash came into season this year, I started putting them into heavy rotation. I love butternut squash soup as it is, but lately I’ve been liking my winter squash on the spicy side. So I make a very simple soup–just leeks, garlic, ginger, and squash, plus enough broth to make it soupy–and add a little dollop of curry paste. Squash loves curry in all forms, and its sweetness really welcomes the spiciness of Thai curry. It makes for a really terrific soup.
I’ve used red and green curry here, and they were both great. The red curry is a cleaner, sourer heat, and I find I need a little less paste to do the job. Green curry is richer, darker, maybe slightly less spicy, and I use a little more of it to really zing. In either case, the effect is both surprising and subtle: lots of fire up front and a quiet thrum of curry in the background.
The soup is nice enough on its own, but adding a little pile of fried shallots to each bowl really makes it special. Pureed squash can be a bit sugary and boring on its own, and the fried shallots add a lovely crackly-crisp texture and bittersweet contrast that I just love. If you’re serving the whole batch of soup at once, I’d suggest frying all the shallots right in the soup pot, then using the shallot-infused oil to make the soup. But if, like me, you like making soup ahead of time and freezing it for later, just fry up a little batch of shallots whenever you’re ready to eat.
I’m not normally one for adding cream to pureed soups, but this soup really benefits from something rich stirred in at the end. The curry paste I use is very spicy, and it needs a bit of fat to tame it so that the other flavors come through. Coconut milk is the obvious choice, but I don’t always want to open a whole can just to use a drizzle. I’ve finished this soup with different dairy and non-dairy milks, depending on what was in my fridge at the time, and it comes out great every time. The recipe includes a bunch of options; use what you like, or what you’ve got on hand. It’s that kind of soup.