Emeril Lagasse wants to cook up a deal to sell his posh Upper East Side townhouse for $15 million. The 6,900-square-foot limestone mansion — with a fabulous chef’s kitchen to whip up some serious eats — goes on the market today, reports The Post’s Jennifer Gould Keil. Gumley Haft Kleier celebrity brokers Michele Kleier, Samantha Kleier Forbes and Sabrina Kleier-Morgenstern are handling the listing at 158 E. 61st St. Lagasse bought the five-bedroom home — with two terraces, a garden and six fireplaces — for $11.5 million in 2009. The celeb chef wants to move to a smaller residence in the city.