As the evenings draw in, leeks come into their own, sweet and mild. Here they melt down slowly in butter, then meet a handful of toasted nuts and a spoonful of mascarpone to make a sauce that clings to every twist.
Why it’s so good: Toasting the walnuts brings out their bittersweet, almost buttery depth, while starchy pasta water turns the mascarpone glossy rather than heavy. Crisp sage and lemon zest keep each mouthful bright.
Make it easy: Toast the nuts and slice the leeks the night before, then the whole supper comes together in the time the pasta takes to boil.
