And we do mean fire! Firing vegetables into a fine ash may turn out to be the latest culinary innovation.  Frank McClelland, a Boston chef, restaurant proprietor, and an organic farmer, likes to coat his food in vegetable ash.

Perhaps no culinary professional has embraced this new trend with such fervor as Mr. McClelland, who says he was inspired by the supply of vegetables—from onions to beets, kale to kohlrabi—from his farm that he could tap for his ash-making experiments. “It’s a complex flavor, but in a good way,” says Herbie Bohnet, a Boston attorney who sampled some of Mr. McClelland’s vegetable-ash covered fare. And it’s a flavor that has Mr. McClelland’s clientele, who can pay up to $200 for a tasting menu, clamoring for more. The chef is thinking about packaging his ash—made from several kinds of burned vegetables—for sale. “Lots of people want to take it home,” he says.

Mr. McClelland approaches crafting an ash the way Indian cooks approach making a curry, or barbecue enthusiasts a dry rub. He uses ashes from different vegetables and then combines them with a mix of spices, from sea salt to cumin. “It’s almost like blending wine,” Mr. McClelland says. For chefs like Mr. McClelland, the real question is how far the trend can go.  He sees potential for vegetable ash as a kind of breakfast spread—a wake-up call that could work better than jelly atop a buttered English muffin.