Key Lime Mousse2018-01-24
Whisk together zest, juice, sugar, salt, and eggs in a small heavy saucepan. Add butter and cook over medium-low heat, whisking frequently, until thick enough to hold marks of whisk, about 5 minutes. Force through a fine-mesh sieve into a bowl, then quick-chill in an ice bath, stirring occasionally, about 5 minutes. Beat cream until it holds stiff peaks, then fold into custard gently but thoroughly. Spoon into glasses and chill at least 2 hours and up to 12.