Bring 2 inches of water to a simmer in the bottom of a double boiler or in a saucepan.
In a bowl (use a heatproof bowl if you’re heating the water in a saucepan), cream the butter and honey with a wooden spoon until light and fluffy.
Beat in the egg yolks and whole eggs. Whisk in the orange juice and lemon juice, followed by the orange zest and lemon zest, then pour the mixture into the top of the double boiler or set the bowl over the saucepan. Cook, stirring constantly, until the mixture thickens and becomes jellylike, about 5 minutes.
Strain the curd through a fine-mesh sieve set over a bowl to remove bits of egg and citrus zest, then spoon the curd into a jar. Close the lid tightly and transfer the jar to the refrigerator, where the curd will keep for about a week.