Newburg (also spelled Newberg) is a rich, creamy American seafood dish of cubed lobster, shrimp, or crab sautéed and finished in a butter, sherry, and egg-yolk-thickened cream sauce, seasoned with cayenne, nutmeg, and lemon juice. It dates to Delmonico's restaurant in New York City, where chef Charles Ranhofer served it in the 1870s.
By the traditional (though not fully documented) account, the dish was originally called 'Lobster à la Wenberg' after Ben Wenberg, a sea captain and regular customer credited with the idea; after a falling-out between Wenberg and the restaurant's owner, the name was rearranged to 'Newberg' rather than dropped from the menu. It's typically served over toast points or in puff pastry shells so the sauce soaks into the base.
The dish spawned variations using other proteins, generally labeled 'à la Newburg' (Chicken Newburg, for example), though the classic version is built on seafood. Because the sauce is thickened with egg yolks over gentle heat, it must be stirred constantly and kept below a simmer to avoid curdling.