We’re not used to South End openings happening with zero fanfare, but that’s just what happened when Jake Elmets, late of M.F. Dulock, took over the space formerly occupied by Merrill & Co. without so much as a press release or a functioning website. Don’t count on Ipswich Custom staying under the radar for long, however. Elmets did a stint at the legendary Chez Panisse, and his passion for well-sourced ingredients and authentic cooking techniques is on full display. The rotating menu is deliciously eccentric: alphabet soup, lamb collar and lasagna appear one night; tuna belly, roasted olives and flank steak the next. Given Elmets’ butchery background, a charcuterie tasting is a must, as is a dip into the cheeses sourced from Italy and Upstate New York. “Expect a leisurely paced meal,” proclaims the menu each night—we’re happy to sit back and let Elmets dictate our evening.