Big crispy portions flopping on big oval plates eaten with a big knife and fork to big 1950s sock-hop music: The franchise-ready Poppies does for British fish and chips what peppy jukebox diners have done for mid-century American food. For all its plastic theatricality, it hews to authenticity: The chief dish, cooked to order, is sustainably caught and sourced from third-generation fishmonger T. Bush at Billingsgate Market, and even the uniforms worn by the “Poppetes” waitresses—a red sailor frock with a jaunty, bellhoppy cap—come from Collectif in Camden’s Stables Market. For those whose palates swerve differently, there’s also chicken, the chance to try jellied eels, and lusher green salads than most London establishments serve. There’s a second location near the markets of Camden Town (30 Hawley Crescent., NW1; [tel] 020/7267-0440).