In a small saucepan, bring the vegetable broth to a boil then add the tvp to it, cover and kill the heat. Let sit for 10 to 15 minutes.
Meanwhile, heat the avocado oil in a large skillet set over medium heat. Add onion, garlic and celery and cook until slightly softened and fragrant, about 2 minutes.
Add the mushrooms and continue cooking for a few minutes, until they start to release some of their moisture, then add the carrots and potatoes and stir to coat.
Add the soaked TVP along with the vegetable broth, followed by the salt, black pepper, herbes de Provence (or other dried herbs or your choice) and 1/2 cup of water.
Bring to a low simmer, cover and cook for about 15 to 20 minutes, or until the potatoes are fork tender.
Dilute the corn starch in the cashew milk (or other non-dairy milk of your choice) and add that to the simmering mixture. Bring the sauce back to a simmer and continue cooking stirring constantly for a full minute then kill the heat.
Stir in the frozen green beans and transfer the mixture to an 8"x8" baking dish.
Make the biscuits
Preheat your oven to 450°F
Drop the 2 tablespoons of coconut oil and vegan butter onto a small plate lined with parchment paper, flatten slightly and place in the freezer for about 10 minutes.
Combine apple cider vinegar and almond milk to make vegan "buttermilk". Set aside.
In a large mixing bowl, combine the flours, baking powder, baking soda and salt.
Take the fats out of the freezer and, working quickly, chop them as finely as you can with a sharp chef knife. If you find that the chopping action has made the fats soft again, return them to the freezer for a few minutes.
Add the cold, finely chopped fats to the flour mixture and mix well with a wooden spoon or rubber spatula. Check the consistency of the mixture with your fingertips; it should feel like coarse sand. If you find the odd larger chunk of fat, simply break it down with your fingers.
Make a little well in the center of the mixture and pour in the cold "buttermilk". Stir delicately until the dough just barely comes together; it will be very sticky.
Turn the dough onto a floured work surface, dust the top with a little bit of flour and gently pat the dough out into a 1" thick round, rotating often to ensure the dough isn’t sticking. Cut out 9 biscuits with a 2-1/2" round cookie cutter.* Be sure to push straight down through the dough without twisting, as doing so might prevent the biscuits from rising.
Arrange the biscuits over the vegetable mixture, brush the tops with a little bit of olive oil and bake in the preheated oven for 15-20 minutes, until the biscuits puff and turn slightly golden brown.
Remove from oven, garnish with a little bit of chopped parsley, if desired, and serve without delay.
*You should be have enough leftover dough to reshape it and cut out 3 more biscuits. Just be sure to work the dough as little as possible (biscuits from leftover dough will not be quite as puffy as those from first pass, but they'll still very decent!) Place the extra biscuits on a small cookie sheet and bake them alongside the pie for about 15 minutes.