Vegetable ash, unlike polyester in a leisure suit, is both timeless and trendy.

For centuries cheesemakers have used vegetable ash – typically discarded bits of vegetables that are charred and then pulverized – for both aesthetic and preservative reasons.

A line of dark ash mixed with a bit of salt running down the middle of snowy white cheeses like France’s Morbier, California’s Humboldt Fog or Maine’s own triple-layer Sea Smoke from Sunset Acres Farm and Dairy in Brooksville, is visually very interesting. The ash provides a protective coating for these bloomy rind cheeses, and its alkaline composition helps balance its acidity levels so that it can ripen fully.

Ash turned trendy when hyper-local Nordic chef René Redzepi at Noma in Copenhagen served shrimp with a sprinkle of leek ash back in 2009. It’s since made its way into restaurants around the world, even showing up in the adventurous cooks’ blogosphere. It’s used to add an unexpected smoky flavor to anything from poached cauliflower to fried eggs.

To make leek green ash, chefs grill the greens until they are well charred, then bake them in a hot oven until they are totally black. They cool the shards and process them to a fine powder using a coffee grinder.

Leek green ash is a trendy way to answer the question of what to do with the dark green ends of leeks that most recipes say to discard after using only the white and light green parts of the allium.

A better root-to-stalk solution is to throw them into the stock pot. Or use them to create leek broth (much like pea pod broth) to flavor risotto of all kinds, especially since the whites and light green bits are already sweating in the pan, even before the short-grained rice goes in. The dark green ends have less flavor, so the result is a subtle layering of flavors, not an overpowering oniony one.

According to gardening guru Tom Atwell, Maine leeks are best harvested in the fall, after a couple of good frosts. So it’s stew season when local leeks peak. The top part of a leek branches out in a V-shape. If you cut the leek at the stalk just before it begins branching and then make a second cut 4 inches beyond the first, you can easily nestle herbs inside it, tie it up with kitchen twine, and use as a bouquet garni to flavor long-braised beef, chicken and bean dishes.

Or you can line a steamer – either a traditional Asian bamboo variety or a modern metal one – with split and flattened leek greens to prevent your steaming dumplings or fish from sticking and serve as a subtle flavor agent.

But excepting the ash option, though each of these uses extracts flavor from the leek tops, the bulk is still headed for the compost pile, or worse, the municipal landfill.

I want ways to eat, preferably enjoyably, leek tops.

Italian cookbook writer and restaurateur Lidia Bastianich includes them in her recipe for “A Smooth Sauce for a Couple of Tough Veggies” in “Lidia’s Family Table,” writing she wants to feel virtuous about not wasting tasty food. She combines asparagus stubs, several leek and scallion tops, garlic and onions in water and simmers them for an hour. She purees the simmered vegetables with fresh parsley to ramp up their otherwise army green color, pushes them through a sieve, and tosses the sauce with pasta.

Minus the asparagus, this is certainly an option for fall leek greens, especially if you’ve any Parmesan rind broth hanging out in your freezer so that you can simmer the vegetables in broth rather than water.

I attempted to expand on Bastianich’s technique, simmering tops from a single leek in coconut milk and pureeing the mix before using it as a base of a vegetable curry. “The dish is just kind of bland, but the color and the texture of the sauce is really pretty revolting,” my husband said, hopeful that honesty was a policy for which he’d not pay dearly in this case.

He was right. The long simmer had unleashed an okra-like slime from the leek. While a little of this mucilage (a polysaccharide substance extracted as a viscous or gelatinous solution from plant roots and used in medicines and adhesives) is handy for thickening a sauce, I’d clearly overdone it.

But if leek greens act like okra, why not borrow a cooking method I use to keep okra’s slime at bay? Julienned, the leek tops worked a charm in Indian chef Suvir Saran’s crispy okra salad (see adapted recipe). Alternatively, you could cut the leek greens crosswise in 1/4-inch slices, and dredge them in egg wash and then cornmeal before frying like okra.

In either case, the results are neither bland nor revolting. And, dare I say, even better than the ash.