Whisk yolks, eggs, honey, sugar, zest, orange juice, lemon juice, and a pinch of salt in medium saucepan until smooth. Cook over medium-low heat, stirring constantly with whisk or rubber spatula, until mixture thickens slightly and registers 172°F, 8–10 minutes.

Off heat, whisk in chilled butter until melted. Strain lemon curd through fine-mesh sieve into a bowl. Press a piece of plastic wrap against surface of curd and chill 2 hours, or until set.