Set up a bain marie or heat-proof bowl over simmering water.
Add the egg yolks, lemon juice and zest, and honey. Use a whisk to stir and combine the ingredients.
Slowly add small pieces of butter until it’s all in the bowl. Whisk the butter into the mixture as you add it.
Gently simmer and occasionally blend the mixture until it thickens (about 5 minutes). Try not to let it get clumpy.
Once it is the consistency of custard, take it off the heat, cool in a bowl or pan of cold water to stop it from cooking, and then store it in the refrigerator to use in yogurt, as cupcake filling, or on toast.