Step 1

Melt the butter in a small saucepan on low heat.

Step 2

Remove from heat and whisk in sweetener, lemon juice, and lemon zest until dissolved. Whisk in the egg yolks and return to the stove over low heat. Whisk continually until the curd starts to thicken.

Step 3

Remove from the heat and strain into a small bowl.

Step 4

Let cool to room temperature, then cover and store in the refrigerator for up to one month.