Grant Achatz, the acclaimed Chicago chef whose battle with tongue cancer has made him a hero to the culinary world, is a rare sight in New York. Arguably the country’s most praised chef for his high-tech wizardry at Chicago’s Alinea, his appearance at the New York Wine & Food Festival is sold-out, and only a handful of tickets remains for his appearance at the Gourmet Institute. So it’s good news for the chef’s many admirers that a third appearance is planned for November 6 at the Astor Center. It’s described as a “book release/cooking demo/Champagne-and-appetizers party” and will feature not only the chef but half a dozen people from the Alinea staff. It’ll be another tough ticket — there are only 100 that will be made available — and they won’t go on sale until the fall. Expect an announcement from the Astor Center after Labor Day.