1. Grease and line a 7-inch round springform pan with parchment paper
2. Finely grind almond and walnuts in a high-speed blender. Combine ground almond and walnuts with melted coconut oil and mix to combine fully.
3. Transfer the almond-walnut-coconut oil mixture to the springform pan and use the back of a spoon to press down the crust mixture as firmly as possible. Let crust chill in the refrigerator for at least 30 minutes.
4. As crust is chilling, place soaked cashews in the blender together with almond milk, water, fresh lemon juice, and blend until you get a thick cream. Add in lemon zest and sugar and blend some more. Dissolve agar agar powder in 1 tablespoon of warm water and add in to the mixture together with the melted coconut oil. Blend until you get a homogeneous mixture.
5. Pour lemon cashew cream filling over the prepared crust and freeze for at least 2 to 3 hours until filling is firm before serving.
6. Remove from freezer 10 minutes before serving to soften slightly and top with and lemon slices and/or berries, to serve.