I first had the ice cream at Blue Hill in Greenwich Village. The chefs, Dan Barber and Alex Urena, got the idea from Pierre Reboul, pastry chef at Vong in Midtown. Their version is milky and light. Mr. Reboul's is custardy. Both are unforgettable.
Mr. Reboul tried it after recalling how a single kernel gave his mother's apricot jam a perceptible scent when he was a child in France. Infusing cream, milk and eggs with kernels brought out the flavor even more.
At Vong, the apricot pit ice cream is called bitter almond ice cream so customers are not wary. Fruit pits contain cyanide.
''It's the plant's way of protecting its young, making the seeds poisonous to animals, so the animals don't choose it as a tasty snack,'' said Shirley O. Corriher, a biochemist and the author of ''Cookwise'' (William Morrow, 1997). But she said that using the kernels as an aromatic is much less risky, and that it would take a lot of kernels to harm an adult. (A derivative of bitter apricot kernels called laetrile was actually once touted as a curative for cancer, but was proved useless.)
Apricot pit ice cream is not a flavor children would appreciate. It is best served in small amounts. The ice cream is powerful but one-dimensional and comes to life only with other flavors. Ms. Shere serves it with lemon ice cream, berries, fruit pies and chocolate or caramel desserts.
The recipe seems ridiculous at first. It calls for about 45 apricots. But you can mix apricot pits with those from plums, nectarines, and peaches. And you can save them in the refrigerator or freezer until you have enough.
Wrap apricot pits in a heavy dish towel. On the floor or on a sturdy cutting board, crack pits open using a hammer or a meat mallet, exposing kernels. Watch your fingers.
In a medium saucepan, combine apricot kernels and shells with milk and heavy cream. Bring to a boil; turn off heat and let cool. Chill overnight in refrigerator.
The next day, bring the milk mixture to a boil again and strain through a fine sieve. Meanwhile, in a large bowl, whisk together the sugar and the yolks until light and fluffy. Whisk about 1/2 cup hot milk into the egg mixture, and then whisk the egg mixture into the milk. Pour into a large saucepan, place over medium-low heat and, stirring constantly with a wooden spoon, cook until thick enough to coat the back of the spoon. Remove from heat immediately. Let cool, and then strain.
Pour into an ice cream maker and follow manufacturer's instructions.
Before starting Food52 with Merrill, I was a food writer and editor at the New York Times. I've written several books, including "Cooking for Mr. Latte" and "The Essential New York Times Cookbook." I played myself in "Julie & Julia" -- hope you didn't blink, or you may have missed the scene! I live in Brooklyn with my husband, Tad, and twins, Walker and Addison.