For this creamy pasta that’s rich yet not cloying, we took our lead from the Middle Eastern technique of using yogurt as the base for a no-cook pasta sauce. We add a generous amount of cilantro for freshness and color, toasted nuts for depth of flavor and softened butter for richness. Toasting a portion of the pasta adds another layer of earthy, wheaty flavor. We especially liked the subtle heat and cumin notes of Aleppo pepper in this dish, but if it isn't available, substitute 1½ teaspoons sweet paprika plus ⅛ teaspoon cayenne pepper or red pepper flakes in the yogurt mixture, then sprinkle the finished dish with ½ teaspoon sweet paprika just before serving.