1/2teaspoondiamond kosher salt (if using any other salt, use half the amount)
1stickunsalted butter, , cold and cubed
1egg
1/2teaspoonvanilla extract
Instructions
Shortbread Crust
Place almond flour, all purpose flour, and salt in a small food processor. Pulse to combine.
Add in butter and pulse until butter are very small pieces, just a bit smaller than a pea. This will require about 30-40 pulses- be patient.
Add in egg and vanilla extract and pulse until combined and dough has congregated into a mass. At this point, check to see how sticky it is- if it is sticking to your hand significantly, add in a tablespoon of flour at a time until it is less sticky.
Shape dough into a ball and then into a disc. Wrap in plastic wrap and place in fridge for at least 2 hours, up to 1-2 days.
Assembly
Preheat oven to 350.
After shortbread dough has been refrigerated, press dough into tart pan. To do this, split the dough in half. Take one half, and split it into four quarters (for the edges). For each side, roll out the dough into a small log and then press into each side. Then take the other half and press this into the center. The dough should be pressed until it is quite thin- this is ideal! Don't worry.
Bake crust until lightly golden brown, about 20-25 minutes. Let set aside and cool.
Blood Orange Curd
In a medium bowl, place eggs and egg yolks. Whisk to combine. Set aside.
Place lemon juice, orange juice, arrowroot, and sugar in a small sauce pot. Heat over low to medium heat, stirring frequently with a whisk, until it boils. Right after it boils, immediately remove from heat and pour into bowl with eggs, whisking the eggs while you pour- the key is to incorporate this hot mixture into the eggs off heat and whisking continuously so the eggs don’t cook, but start to get warm. A quick shock of heat is not good for the eggs- a more gradual increase of heat will result in a better consistency.
Pour this egg mixture back into the saucepan and put over a very low heat. Whisk the ENTIRE time until the mixture thickens, about 3-8 minutes and the temperature registers around 160ish. Some notes here if you want the perfect curd and minimize error:1. DON’T LEAVE THE POT and whisk the whole time. Seriously. I’m the biggest multitasker ever when it comes to cooking and I don’t leave this pot. The likelihood of accidentally cooking the egg is too high)2. Technically the end temperature should be higher but after doing this about 10 times, I found that 160 works best. I’ve also found a huge discrepancy in how long this takes- sometimes it happens immediately, sometimes it takes longer.3. Pay attention to whisk the corners and sides of the pot, as it’s easy for egg to get stuck here and then cook. At end, change to a wooden spoon or spatula so you can get a better sense for how thick the mixture is. The texture/consistency you want is that it sticks to the spatula and when you run your finger through the back of the spatula, it doesn’t run.
Remove from heat and add butter, a few cubes at a time, stirring until fully incorporated. Once smooth, add into cooled shortbread crust.
Lower oven temperature to 300 degrees. Bake until the center of the curd is set but still has a slight wobble to it, about 30-35 minutes.
Let tart cool completely. Place in fridge for at least an hour before slicing and serving.