new to lennox hill
You may want to start a search for "Upper East Side" or "East 60s-70s-80s", and you'll find numerous discussions and recommendations, often grouped by type of cuisine or restaurant. For what it's worth, Lenox (one "n") Hill is not often used as a neighborhood name, despite the presence of the post office, hospital and the big settlement house by that name. Do try Luke's Lobster Shack on 81st for great lobster rolls, and I Quattro Gatti also on 81st for carefully prepared old-school Italian American. There are countless more. Good luck.