This time of year always makes me anxious: so many squashes, so little time. Farmers markets are all cascading with kabocha and buttercup and other varieties with deep flavors and short seasons, and I can’t bake and butter them fast enough.
But the squash that gets chefs thinking is none of the above, and that’s extremely calming. Pick up a menu in a high-end restaurant, or look over the choices in a takeout shop, and odds are the soup special is butternut squash. No matter that this is one squash that’s available anytime, anywhere. Familiarity somehow breeds inspiration.
Butternut squash is the empty canvas of the vegetable world. Alone, it has a sublimely smooth texture and just-sweet-enough flavor. But when it’s seasoned and garnished or otherwise embellished, it can be elevated to art. Something as simple as chopped ginger adds as much impact as overly indulgent cubes of sauteed foie gras. And unlike other soups made from common vegetables, whether carrot or potato, butternut’s identity never gets lost no matter what garnishes are added.
Just a couple of years ago chefs were equally besotted with another unlikely candidate for soup stardom, celery root. Now it’s easy to understand why they have turned back to butternut squash. Its very name sounds like the essence of autumn, despite its omnipresence in supermarket produce aisles all year round.
It has the highest yield of any squash, with very low seed-to-flesh ratio, and it’s definitely the easiest to prep, with a sleek skin so thin you can whisk it away with a potato peeler.
But most important, it’s the ultimate chameleon. A little chorizo can orient it toward Spain, a little curry powder toward southeast Asia, a crumble of Gorgonzola toward Italy.
Creamy or caramelized
Butternut squash soup is also simplicity itself, which may be one reason you won’t find it in a can. You can just add peeled chunks of the raw flesh to simmering stock, then puree it and get an exceptionally satisfying bisque, with or without cream. Or you can bake a halved and seeded squash until it caramelizes to amplify the flavor with even less work, then puree it with stock. (Teamed with caramelized roasted garlic, it’s amazing.)
You can change the soup’s character at the beginning of cooking, or, at the end, by garnishing it with anything that adds flavor (crumbled Maytag blue, slivered smoked turkey) or crunch and flavor (chopped pecans, toasted pumpkin seeds, crumbled smoky bacon). And butternut squash soup takes well to aggressive flavorings, particularly red or green Thai curry pastes, cumin or chipotle chiles.
I don’t have a sweet tooth, but even I’ll concede that butternut squash is improved by spices usually destined for pumpkin pie: cinnamon, ginger, nutmeg, mace and allspice. Cardamom will also add a high note. When going this route, dried cranberries are a natural garnish.
Simmering the squash with other ingredients, whether fruits or vegetables, makes the soup more complex. Apples, pears, even bananas are all good complements even when you’re starting with water or with the holy trinity of soup flavorings: onions, celery and carrots. (Leeks instead of onions produce an even more balanced soup.)
Because butternuts have an inherently rich flavor, you may choose to make soup from them using nothing richer than water. Homemade turkey or chicken stock is best, though, unless you want more of a Southeast Asian flavor with coconut milk substituting. In any case, you don’t want to shortcut the soup by not starting with aromatic vegetables and cooking carefully. The richest garnish cannot compensate for a flavor-free puree.
In fact, one of the best butternut variations I have ever tried was from a recipe from Brigtsen’s restaurant in New Orleans.
It starts with a stock made from shrimp shells, which adds one level of flavor; is enriched with the pureed shrimp themselves, which adds texture and another level; and is finished with a small dairy’s worth of cream, which melds all the tastes into one rich potful.
If you’re in the mood for other kinds of excess, a splash of Cognac or Calvados will do the trick. And if you want the seafood-squash contrast with less work and no cream, just garnish the soup with seared scallops or sauteed shrimp.
Butternut squash soup can survive any garnish, even the one at a high-end French restaurant in New York that combines no less than cinnamon marshmallows, orange zest, nutmeg and huckleberries.
All that would be lost on a kabocha.