Heat oil in a large skillet over medium heat. Add onion, leek, yellow squash and asparagus. Sauté until tender, about 5 to 6 minutes. Add 2 cups chicken stock and coconut milk, and bring to a gentle boil.
In a small bowl, add arrowroot powder and a tablespoon of cold water. Whisk to combine. Add gradually to vegetable mixture, stirring constantly, until mixture thickens. If your mixture becomes too thick, add a bit more stock, stirring constantly until you reach a desired consistency. Season with salt and pepper, then stir in cooked chicken and herbs. Pour pot pie filling into a 13 x 9 inch baking dish, set aside.
Preheat oven to 400 degrees F (205 degrees C).
In a large bowl, add coconut flour, baking soda, salt and pepper. Whisk to combine. In a medium bowl, add eggs, coconut oil, coconut milk, apple cider vinegar and 2 teaspoons of water, then whisk until frothy. Pour liquid ingredients into bowl with dry ingredients, and stir to combine.
Spoon topping batter over pot pie filling in eight equal portions. Bake 20 to 25 minutes or until filling is bubbling and topping is deeply golden and a little crusty. Serve with a garnish of minced parsley.