As winter yields to spring, the land and water surrounding the Culinary Vegetable Institute are teeming with activity. It is a precise, seasonal point in time when nature offers precious and plentiful gifts to seize and savor before the special moment is gone.

The natural rhythm of freezing nights and warmer days releases the flow of sap running through the black walnut trees lining the CVI property. That means the time is ripe for tapping the trees and collecting their crystal clear liquid for transformation into syrup.

 Syrup Tap: Go With the Flow

 On a sun-soaked morning in early March, CVI Chefs Jamie Simpson, Tristan Acevedo and Dario Torres set out with a hand drill, a galvanized pail full of spouts (called spiles), a hammer and a crate full of bottles. Against the grey March sky, all of the towering leafless deciduous trees appear relatively similar. To the untrained eye, which trees are Black Walnuts is anyone’s guess. The dead giveaway is underfoot in the litter of fallen walnuts scattered on the ground. Before driving in the first spile, Chef Jamie cracks open a shell to sample the sweet, tender, tannic nutmeat. “We might be able to use some of these,” he says, hopefully.

At the first tree he has identified for syrup tapping, Chef Jamie drills through the bark, about two inches deep in a conical fashion. Almost immediately the clear watery sap bleeds from the tree’s flesh. He sets a spile and taps it gently to secure it into the wood, then suspends a bottle to collect the sap one precious droplet at a time. Then it’s on to the next.

Sweet Reward

For three weeks the chefs will take turns visiting the trees to collect each day’s accumulation. Some of the bottles are brimming, others less so. An unexpectedly long freeze causes a few to crack and spill their contents but, in the end, the eight trees produce about five gallons of sap.

The watery fluid is unexpectedly free of debris of any kind. “Obviously there’s some kind of filtration going on,” says Chef Tristan. “The tree is one big filter.” The sap from the bottles is as bracingly cold as it is clear. He pours himself a palm full and drinks. “That’s a good beverage.”

He’s right. The water is impossibly quenching. Not sweet exactly, but like something you’d want to chug ice cold from a bucket on a scalding hot day.

Keep it Simple

 Not far from the tree line where the sap flows, steelhead trout are following the flow of the Huron River, which borders the CVI property. The fish are eager to spawn and are filled with blood-orange pearls of glistening roe. The river water is clear and ice cold. It’s the time of season when steelhead are at their best.

CVI kitchen porter Jeff Pfistner is a fisherman, and he has hooked two impressive fish about a quarter of a mile upriver. And soon, these few simple elements, two fish and the sap of eight walnut trees, will be the foundation of a single dish celebrating the abundant seasonal resources that exist just beyond the CVI doors.

The walnut sap is boiling away in heavy pots set over an outdoor charcoal fire. In several hours, the five gallons will fully reduce into finished syrup. The yield will be an infinitesimal fraction of the original volume. “We’re hoping to get a cup,” Chef Tristan says.

Meanwhile, the chefs clean the nearly five pound fish. The eggs are perfect spheres contained inside a membranous sac called a skein. The teeming egg sac is about the length and shape of a full-sized Toblerone candy bar, and slips from the fish’s belly cavity entirely intact.

The chefs prepare the fileted fish in a cure of salt, brown sugar, bay leaf, peppercorns and Chef’s Garden thyme and mountain mint. “The fresh herbs are both really aromatic and infuse quickly,” Chef Tristan says. “All of that flavor goes into the flesh itself. For such a small percentage of the recipe, they’re a huge percentage of the final flavor. That’s really their role.”

 Roll, Roll, Roll Your Roe

As the fish cures, Chef Tristan rolls the trout roe through a grate, using his fingers. The tiny eggs seem unexpectedly resilient. “They can’t be too delicate,” he says. “Otherwise they’d never survive.” The eggs gradually let go and fall through the grate leaving only the remnants of the skein behind. In keeping with the CVI’s no-waste kitchen policy, Chef Tristan says the bits of membrane will be put to future use. “All those little stringy bits we’ll use for bait,” he says, “so we can catch more fish.”

The young chef seems mesmerized by the shining collection of individual vermilion jewels. “What an ingredient,” he muses. “You can’t make that.” He rinses the roe repeatedly with brine to remove remnants of skein and blood, then sorts them like beans for a final check. Emancipated from the vascular sac, the eggs are a paler now, the shade of tangerine pulp.

When the walnut syrup is fully reduced, it is the color of a copper penny and there is just enough to cover the bottom of a large pan. Its sweet, rich caramel flavor is toasty and woodsy from the fire that cooked it, a delightful taste reminiscent of Cracker Jack. Chef Tristan stirs a spoonful of syrup into the fish eggs, causing them to gleam like they’ve been machine polished.

 Homage to a Moment in Time

The chef makes a consommé of some reserved unreduced walnut syrup, dashi, shaved bonito, seaweed, dill blooms and mountain mint. He chars a pine bough from the property, and places roasted Jerusalem artichoke and the cured fish on top to capture the smokiness, then purées the artichokes with some of the foraged black walnuts and scalded milk into a smooth custard.

To assemble the dish, Chef Tristan plates triangles of cured fish, which he’s also glazed with the black walnut syrup. Alongside goes the quenelle of custard and three small mounds of sweetened roe. He garnishes the dish with spring-themed watercress blooms, Calvin pea tendrils, chickweed, cukes with blooms, petite snow peas, dill blooms and micro mountain mint. The final element is a shallow lake of piping hot maple water consommé to surround the composed elements.

The dish, the chef says, is “a moment in time at the CVI, when the components were all right here at the same time.” It is the purest expression of seasonality, a celebration of nature’s provision rendered on a single plate, at a precise time in a specific place. And then it is gone.