In a large stainless steel mixing bowl, whisk together eggs, yolks and granulated sugar. Whisk in the blood orange juice, lemon juice and blood orange zest.

Bring a pot of water to a simmer. Place bowl over simmering water and cook curd, while stirring with a whisk. Continue to cook until curd begins to thicken, about 10-12 minutes. Remove from the heat.

Whisk in butter until melted and well combined.

Strain the curd through a fine mesh sieve. Chill for at least 2 hours before enjoying. You can make the curd three days in advance.