Zest @lemons{4} into @granulated sugar{1%cup}. Rub them a bit to extract all the oils.

Juice the same @lemons{} until you have about 2/3 cup of juice. Strain out the seeds.

Crack @large eggs{4} into a pot and beat lightly with a whisk. Whisk in the zesty sugar. Stir in lemon juice.

Heat on low, while stirring constantly with a whisk until the mixture thickens, just starts to bubble, and coats the back of a spoon.

Remove the pot from heat, then add the @butter{1/4%cup}(cold) and mix until melted.

Strain the curd into a sealable container and refrigerate to firm up.