Perhaps no new Oakland restaurant has made as big a splash as Haven, Daniel Patterson’s latest venture. Chef Kim Alter, who helms the restaurant, has a penchant for experimentation — especially for wild riffs on familiar comfort-food favorites — which has immediately placed her among the ranks of the East Bay’s most creative cooks. Not every experiment was a success during the restaurant’s initial months, but our favorite was one of Haven’s earliest signature dishes: a deconstructed shepherd’s pie that eschewed two of the pub classic’s most basic ingredients, the lamb and the mashed potatoes. Instead, Alter used ground pork butt that had been seasoned with winter spices and, most surprising of all, a light potato espuma — a foam, basically. And yet: It was as tasty and comforting a dish for a cold winter night as any traditional shepherd’s pie we’ve ever had. Haven’s menu changes frequently, but hopefully Alter will bring this dish back soon.