First, make the dough. Place all the ingredients in a food processor and pulse until it all comes together. Next, wrap with plastic and chill for 30 minutes.
Preheat oven to 350 degrees F (176 C).
Dust work surface with some flour and roll out pastry until 1/8” thickness. Roll dough onto rolling pin then invert onto tart pan. Quickly press down into sides.
Use a pairing knife to cut the excess off. Use a fork to dock the pastry all over. Place the pastry in the freezer for 10 minutes.
Before you bake, cover the pastry with a small piece of parchment paper, then fill with rice or beans to blind bake the tart shell. This is the only time the tart will be cooked so it needs to cook all the way through.
Bake for 15 minutes, then remove the parchment and rice and bake another 7 minutes or until golden brown edges.
While the tart shell is cooling, make the orange curd.
Set up a double boiler with simmering water.
Combine blood orange juice, zest, lemon juice, sugar and eggs, in a bowl and place over simmering water.
Whisk while the steam cooks the eggs for about 10 minutes. The custard should turn pale and double in size. Add cubed cold butter and take off heat. Whisk until butter is thoroughly combined.
Pour curd into pastry shell then chill for about 2 hours.
Lastly, make the meringue.
Setup a double boiler again with simmering water.
Place egg whites and sugar in a bowl over the water. Whisk until the sugar dissolves and egg whites are warm to the touch. Transfer to a mixing bowl fitted with a whisk attachment and whisk on high until you get stiff peaks.
Fit a pastry bag with your piping tip, then fill with meringue. Pipe entire amount of meringue onto tart. Use a torch to lightly toast the meringue.
Slice, and ENJOY!