6T butter, unsalted room temp
1 cup sugar
2 egg yolks
1 cup Grapefruit Juice but you could use lemon too, zest of the fruit as well.
Beat butter and sugar 2 minutes. Slowly add the eggs and yolks - mix in each as its added. Mix in the juice.
Its going to look really fucking bad, just bear with.
Cook over low heat, stirring constantly, and it will smooth out. FOR GODS SAKE DON’T LET IT BOIL! Keep going until temperature hits 170 degrees, then take off the heat and let it cool to do with what you will.
Good on toast, tarts, eating straight, whatever.