Preheat the oven to 170°C for the crust. Lightly grease a tart tin (20 cm Ø) with coconut oil.
Add oats and nuts to a blender and grind to a sand-like consistency. Add coconut oil, maple syrup and salt. Pulse the mixer a few times until the ingredients have mixed into a dough. It should stick together when you squeeze it between your fingers. Otherwise add 2-3 tablespoons of water.
Press the dough firmly into the tart mould. Poke a few holes into the bottom of the crust with the fork. Bake in a preheated oven for about 10 minutes. Allow to cool completely.
Wash oranges and lemon with hot water. Grate the peel of an orange. Squeeze oranges and lemon. Put butter in a metal bowl and melt over a warm water bath. Add sugar, lemon and orange juice and the zest and mix.
Add the eggs and yolks and beat over medium heat, stirring constantly until a creamy consistency is obtained. It takes about 20-25 minutes. Attention: The mixture must not boil, otherwise it will curdle.
Remove the finished Orange Curd from the pot and allow to cool at room temperature for 30 minutes.
Fill the curd into the almond crust. Place in the fridge for at least 5 hours until it has set.
If there is any orange curd left, pour it into a glass and store in the fridge. Use within 1-2 weeks.