Root to leaf and seed to skin

Cut waste and boost flavor with recipes that use the whole vegetable

I pick up a butternut squash in my left hand and pull a peeler across its curves with my right, letting the ribbons drop to the cutting board. I switch to my sharp cook’s knife and hack the squash in half lengthwise, then scrape out the seeds and stringy pulp with a spoon. After chopping the bright orange flesh, I swoop the results of my work into two piles: cubes on the right, everything else on the left.

[Kicking your paper towel habit is easier than you think]

On one side, it’s raw food, destined for the oven; on the other, detritus, destined for the compost bin.

As I consider a drumbeat of statistics about the world’s food-waste crisis, however, the line between those two piles has started to blur. These days, I look for ways to cook the whole vegetable (or fruit) from skin to seeds — and to perhaps redefine the very idea of “scraps” along the way.

The stakes are high: According to a report from the United Nations issued in March, in 2019 households worldwide discarded 11 percent of the food they bought, with food services wasting 5 percent and retail outlets 2 percent. That adds up to a staggering 930 million metric tons of uneaten food, enough to load up more than 23 million 40-ton trucks. Food waste accounts for 8 to 10 percent of global greenhouse emissions, but perhaps most strikingly it occurs against the stark backdrop of hunger, experienced by some 690 million people worldwide in 2019.

In a news release announcing the report’s findings, Inger Andersen, executive director of the U.N. Environment Program, put it succinctly: “Reducing food waste would cut greenhouse gas emissions, slow the destruction of nature through land conversion and pollution, enhance the availability of food and thus reduce hunger and save money at a time of global recession.”

Plenty of strategies can help you reduce food waste at home, starting with cooking more of what you already have before shopping, keeping an inventory and storing food properly to prevent spoilage. But once you’re at your cutting board, it’s worth also looking for ways to use a higher proportion of the produce you buy — by putting peels and stems and seeds to work as valuable ingredients unto themselves.

The problem is that too many recipes for using produce scraps require you to set them aside for a future date when you’ll supposedly find the time to, say, pickle those Swiss chard stems or toast those squash seeds. And if you can manage that, more power to you. I haven’t been so successful, aside from saving some onion and garlic skins and veg trimmings in my freezer for periodic brothmaking. What I’ve started employing instead are strategies for using produce scraps in the moment, in the dish I’m cooking with the rest of the ingredient.

[Why are you still peeling all those vegetables?]

The first step is perhaps the easiest: Peel less. Perhaps you long ago discovered, as I did, that there is no reason to peel carrots, and that giving them a good scrub suffices. Bring that same mentality to other root vegetables: potatoes, sweet potatoes, turnips, rutabagas — even beets. Why did we ever peel so many things anyhow? I blame formal (i.e. French) culinary training and its trickle-down effect on recipe developers and cookbook authors who brought a restaurant-chef standard to home cooks.

“Haute cuisine, high cuisine, high culture ... is about refinement, so it’s about peeling, making things beautiful and into certain shapes,” said Amy Emberling, a co-owner at Zingerman’s Bakehouse in Ann Arbor, Mich. “They connected the idea of something being great to it being refined. If you could afford it, you wouldn’t eat those peels.”

Max La Manna, author of “More Plants Less Waste,” remembers when he cooked at New York City’s ABCV, owned by Jean-Georges Vongerichten. “It was a great experience, but when we would prep food, we peeled everything,” he told me. “We would cut the carrot into a long rectangle. And we’d cut away so much of the vegetable and throw it away just to get these perfectly square sides.”

Besides avoiding food waste, there are other reasons to put the peeler aside. Not only is it a matter of efficiency, said Linda Ly, author of “The No-Waste Vegetable Cookbook,” but you can’t detect a carrot peel when it’s cooked. And there are health implications. “The skins hold quite a bit of nutrition in a plant, so if you’re just peeling something and composting it, you’re losing it,” she said in an interview. “Because I garden, I’m hyper-aware of soil health and microbes and gut health, and there are studies saying dirt in the soil is so good for you, because you’re adding to your gut biome. When you’re peeling, you’re getting rid of that good bacteria.”

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Honey-Roasted Carrots With Carrot-Top Chimichurri

While the roots are in the oven, turn the tops into a tart sauce.

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If you’re worried about pesticides, buy organic produce and wash it well. According to toxicologist Thomas Galligan at the Environmental Working Group, while some pesticides are absorbed by produce through the soil, others are sprayed directly during growing or after harvesting, resulting in more pesticides on the peel than inside. The amount of pesticide on non-organic produce varies widely by fruit or vegetable, so the group issues annual “Dirty Dozen” and “Clean Fifteen” lists, based on Agriculture Department testing that assumes washing and peeling. If you’re eating the peel, he said, the group’s general advice holds: Choose organic produce when possible — especially for the Dirty Dozen. This is especially important, he added, for anything you’re eating raw.

Beyond the pesticide concern, I approach most recipe instruction around vegetable prep with a good dose of skepticism. For years, I’ve resisted the imperative to use just the “white and light green parts” of a scallion, as if there is a detectable taste difference once the green gets dark. The only mushroom stems I remove are shiitake stems because they’re so chewy, and I avoid even trimming others. There’s little reason to trim the root end off garlic cloves, either.

The same perspective applies to greens: Do you really need to separate leaf from stem and use the former but not the latter? With tender greens such as spinach or herbs such as parsley and cilantro, don’t even bother stripping. With hardier greens, treat tougher stems the way you would celery, thinly slicing or finely chopping and sauteing them with your aromatic vegetable base until tender, then adding the leaves later in the cooking process.

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Sauteed Swiss Chard

Don’t discard the stems: They add color and texture.

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If you garden, you probably know to avoid eating the leaves of rhubarb, eggplant and potatoes. But many commonly discarded parts of other vegetables are perfectly edible, including the leaves of the brassicas that we typically grow for their flowers (cauliflower, broccoli, Brussels sprouts). Even after buying cauliflower at the market, use those leaves curling around the head, and don’t discard the core or stem, either.

“The leaves are really thick, and they taste really good,” said Anne-Marie Bonneau, author of “The Zero-Waste Chef.” When she roasted a cauliflower recently, “I cut those up, and the core, too. I peeled the bumpy parts off the core and cubed the core and just roasted it with olive oil and salt and pepper, and in the end I chopped up some preserved lemons and put them in, too, with some herbes de Provence. It was delicious, and there was hardly anything left of my cauliflower.”

Similarly, broccoli stems can seem tough, but except for maybe an inch or so of particularly woody parts, you can peel the stem and chop it for cooking alongside the florets.

You can turn carrot tops into pesto, and beet and radish greens can be cooked just the way you would Swiss chard. But rather than roasting roots by themselves and saving greens for another day (and trying to keep them from rotting in the meantime), give them separate treatments in the same dish. I like to make a tart chimichurri with carrot tops while I roast the bottoms and spoon the former over the latter for serving. Ly braises radishes in a buttery broth, then folds in their greens until wilted.

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Butter-Braised Radishes and Radish Greens With Farro

The roots and greens combine in this balsamic-drizzled grain dish.

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And forget the typical instruction to snap off asparagus spears wherever they seem to “want” to break. That results in much more waste than needed. Better to trim off just an inch or so from the ends, depending on how thick and tough they seem, then peel the bottoms a little if you’d like.

Some peels, of course, seem downright inedible: the outer layers of onions, garlic, avocado and bananas. But even many of those deserve reconsideration. Onion and garlic skins can still lend their flavor to the aforementioned scrappy vegetable broth, but that’s not all. I’ve started leaving the skins on when I add them to a pot of dried beans. The flavor goes into the liquid (and the beans), the flesh almost disintegrates, and the peels are then easy to pick out and compost.

If you’ve followed any viral food trends on TikTok lately, you’ve probably seen cooks making — or making fun of — “pulled pork” from banana peels. I haven’t tried that yet, but I started doing something else with the peels after reading about it in Lindsay-Jean Hard’s book “Cooking With Scraps.” For her banana cake, Hard simmers peels in water until tender before pureeing, but she doesn’t include the banana flesh. In keeping with my goal to use the whole fruit, I wondered: What about a banana bread that uses the flesh and the peel?

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Don’t Peel Your Banana Bread

Freeze the fruit, peels and all, then blend it into the batter.

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Turns out, Hard was way ahead of me. When she went to work with Emberling at Zingerman’s, she suggested just that, and Emberling jumped at the chance to cut down on not only the bakery’s waste but its composting bill. After her book had published, Hard discovered that freezing and thawing bananas softened the peels dramatically without the need to cook them, enough that you could puree the whole fruit before adding it to batter. “People are at first skeptical,” she said. “But they were won over once they tasted it, because it tastes even more banana-y than before.”

The bakery stopped peeling apples for pie and carrots for cake, too, but the whole-banana bread made the biggest splash. It’s among the company’s top mail-order items — Zingerman’s sells between 4,000 and 10,000 loaves of it a month — so including the peels not only helped reduce its compost by 30 percent; it saved money on ingredients by increasing the yield of the bananas and on labor by allowing them to skip the peeling. “Let me be clear: That wasn’t the initial motivation,” Emberling said. “But it’s certainly nice.”

Other peels, such as those on winter squash, seem as if they’re going to be too tough or unpleasant to eat, but it depends on the variety. I don’t peel kabocha and delicata squash before roasting, for instance, and the peels get tender, while butternut’s peel doesn’t. La Manna demonstrates a nifty solution in his Seed-to-Skin Squash and Sage Pasta: Thinly slice the removed peel and roast it with the seeds on a pan separate from the cubes. You’ll get a crunchy, crispy garnish for pasta enrobed in a thick, rich squash sauce.

That’s how I dispatched the piles of butternut squash prep on my cutting board. Thanks to La Manna’s recipe, the line between food on one side and detritus on the other blurred so much it started to fade.

Erasing the line is ultimately about changing your definition of scraps altogether, Bonneau said. “It’s kind of like calling plants weeds,” she said. “It depends on your perspective. They’re all plants, and it’s all food.”

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Seed to Skin Squash and Sage Pasta

The peel and seeds become a crunchy garnish.

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About this story

Photos by Scott Suchman for The Washington Post. Food styling by Lisa Cherkasky for The Washington Post. Props by Limonata Creative. Art direction and design by Amanda Soto. Photo editing by Jennifer Beeson Gregory.

Joe Yonan is the Food and Dining editor of The Washington Post and writes the Weeknight Vegetarian column. He is the author of "Cool Beans," a cookbook about his favorite ingredient.