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With the right tools, preparing butternut squash is easy. [Photographs: Daniel Gritzer]
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For some, the start of football and hockey season marks the transition from summer to fall. For me, it's the butternut squash I've taken home from the market. Of all the winter squashes, butternut is one of the most common and also one of the most versatile. It's firm enough to hold its shape in some dishes, yet purees beautifully in others. It has enough sweetness and flavor to be very appealing, but not so much that it tastes like dessert.
I had some fun playing with butternut squash for the pressure-cooker risotto recipe I developed recently, but cutting it up into all different sizes reminded me that its firmness and odd shape can make it a more difficult vegetable to prepare than many others.

Shopping and Storage

Because they're hard to the touch and covered in a thick, durable skin, the art of gauging the ripeness of a butternut squash comes down to some subtle clues. First, you want to pick squash that are free of any punctures or surface wounds, since a compromised skin can lead to rotten spots pretty quickly. Beyond that, look for squash that feel heavy for their size, and avoid any that have a greenish cast to their beige skin.
I've never put squash to the types of tests I subjected tomatoes to over the summer, but I've always found that they do very well at room temperature, which is also how I usually find them stored at supermarkets. You can thank that thick skin—it's responsible for their shelf stability by providing an incredibly effective protective layer that traps in moisture and keeps out microorganisms.
At root-cellar temperatures (around 55°F or so), butternut squash can keep for several months. In heated homes you're safe holding them at room temperature for many days and possibly weeks, though I can't think of a good reason to find out just how many weeks a squash will hold up on your counter before it starts to break down—eat it, that's why it's there.
When you're ready to cook a butternut, just give it a rinse to wash off any surface dirt and you're all set.

Butternut Butchery

The Right Knife

The first step is making sure you have the right tools. As with most cooking tasks, the main thing that makes cutting up butternut squash difficult is not having a good knife available. Because of the squash's firmness and thick skin, I've always found that smaller, lighter-weight knives make the job more difficult. Instead, I reach for a knife that's not just sharp, but also has some weight to it—that heft will do some of the work for me.
A (roughly) 10-inch chef's knife like the one here will do the trick.
If there isn't a hefty knife around, the next one I'll grab is a serrated knife: Those teeth on the blade will make up for whatever mass the knife itself lacks. As Kenji has pointed out in his own writings on knives, a serrated (A.K.A. bread) knife needn't be an expensive purchase: they're not easy to sharpen so you'll have to replace them from time to time.
As I'll show below, I often peel my squash with whatever knife I'm using, but a peeler can be useful too. And when I use a peeler, I'm really only interested in one kind: a razor-sharp y-peeler. If you're not used to using one, it can seem awkward and difficult at first, but with a little practice I doubt you'd go back to the other kind. I don't think I've ever seen a professional chef use anything but one of these.
You'll also need a spoon for removing the seeds.

Cut off Stem End

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The first thing I do is cut right below the stem of the squash to remove it.

Cut Off Blossom End

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Next, I rotate the squash and slice off the very bottom of the other, more bulbous, end, where the flower had once grown on the fruit (it's not anatomically accurate, but let's call it the belly button). I try not to cut off too much here, erring on the side on not quite getting enough of that belly button on my first pass—if I need to take more off, I can always cut again. Once I've fully removed that bottom belly button, I'm good to go.

Divide in Half Widthwise

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Butternut squash has two sections: The top section on the stem-end side is narrower and filled with solid flesh. The more bulbous section on the flower end (where that belly button was) is hollow and contains the seeds.
I line the knife up right where the narrow section meets the bulbous section and split the squash in half there.
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You should now have two sections of squash: the top portion and the bulbous seed section.

Peel

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If you have a peeler, go ahead and strip the skin off with it. You want to peel down to the orange flesh, cutting away any white or light-colored flesh directly below the skin, as well as any green veins that run lengthwise under the skin.
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If you're not using a peeler, sit each section of squash on a flat end and slice around it, either with a sharp knife or a serrated blade (my photos here show both), to remove the skin.
Also, can we stop and appreciate my freakishly double-jointed thumb in the photo above?
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Repeat the peeling for both the top section and bulbous seed section of the squash.
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Split Seed Section

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Next, I stand the seed section on a flat side and slice it in half lengthwise.
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Remove Seeds

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Using a spoon, I scrape out the seeds and any of the fibrous flesh that's attached to them.
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If you like to eat pumpkin seeds, don't throw these away: They can be toasted and enjoyed as a snack. (I'm not so crazy about pumpkin seeds, so I usually toss 'em.)
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Slice and Dice Seed Section

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I take each hollowed seed section half, sit it hollow-side down on the cutting board, and slice it lengthwise into sections. You can go as thin or as thick as you want here: That will determine the size of your pieces. You can cook these curved slices as-is, or dice them.
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To dice them, just cut each slice into chunks of your desired size. Because these curved pieces of squash are not perfectly regular in shape, you won't get perfect cubes here, but that's okay. Nature doesn't grown too many things with flawless right angles.

Slice and Dice Top Section

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If the top section of the squash is particularly long, I'll split it in half widthwise to make it more manageable.
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Then I stand it on end and slice down in even intervals to form slabs. Here, I'm doing a roughly 3/4-inch dice, so that's the width of each of my slabs. You can go thicker or thinner depending on your specific need.
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Once I've cut it into slabs, I cross-cut those slabs into batons.
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Then I rotate those batons and cut them into dice.

Alternate Cut: Circles

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The top section of the squash can also be sliced into rounds.
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To do so, I turn it on its side and slice through it widthwise.
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Again, you can go as thick or as thin as you want here.

Take Two: Small Dice

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If you want smaller dice, all you need to do is make thinner cuts on both the seed end and the stem end. Here I'm demonstrating it on the stem end.
Start with the stem section of squash on its end and cut down through it lengthwise, making your slices much closer together.
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Then slice those thinner slabs into much thinner matchsticks.
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And cross-cut those matchsticks into tiny cubes. These are roughly 1/8-inch. Aren't they cute?
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