3 large lemons
3/4 cup granulated sugar
3 large eggs
1/2 cup unsalted butter, cut into pieces
Zest the lemons
Juice the lemons
Whisk lemon juice, lemon zest, sugar, and eggs in a heatproof bowl
Place the bowl over a saucepan of simmering water
Stir constantly until the mixture thickens
Add the butter pieces and stir until melted and smooth
Strain the curd through a fine-mesh sieve
Transfer to a jar or container
Chill until set