Preheat the oven to 375 F and line a baking sheet with lightly greased parchment paper.
Prepare the flax egg by combining the ground flax with 3 tbsp water in a large bowl. Stir to combine and allow to sit for 5 minutes.
Add the coconut flour, arrowroot starch, and baking soda to the bowl and stir to combine. Stir in the remainder of the crust ingredients and stir until a dough forms.
Add the dough to the baking sheet and flatten it into a long oval crust.
Transfer to the oven and bake for 7 minutes.
Remove from the oven and carefully (don't burn yourself!) top with the dairy-free cheese, spreading into an even layer. Add the apple slices, making sure the apples don't overlap and return to the oven for another 5 minutes.
Remove from the oven and allow to cool slightly before topping with arugula, prosciutto, olive oil, balsamic glaze and pepper. Slice and serve fresh.