Preheat the oven to 400 degrees. Toss the mushrooms with salt and pepper. Use a cooking spray to spray a baking sheet and place the mushrooms on the sheet, trying not to overcrowd and overlap.
Place the baking sheet in the oven and roast the mushrooms for 20-25 minutes until they are dried out. Place the mushrooms in a food processor and pulse 10-15 times or until you have a coarse mince. Set aside.
Heat the oil. Add the onions, carrots, and celery. Season with salt and pepper and saute until the vegetables are softened and the onions translucent, about five minutes on medium heat
Add the garlic and thyme. Stir well to mix for about a minute. Add green peas and saute until thawed and warmed through, about three to four minutes.
Add the quinoa, minced mushrooms and tamari. Mix well and let it all heat through. Add more salt and ground black pepper if needed. Turn off the heat and set aside.
Make the topping
Preheat the oven to 450 degrees. Place the sweet potatoes on a baking sheet, preferably lined with aluminum foil. Pierce the sweet potatoes in several places with a knife. Roast for 45 minutes or until the potatoes are thoroughly cooked and oozing liquid.
Mix the olive oil, crushed garlic, and red pepper flakes in a small bowl and set aside.
Peel the roasted sweet potatoes and mash them into a bowl. Add the coconut milk and some salt and ground black pepper to taste.
Assemble the pies:
Preheat the oven to 400 degrees. Scoop the filling into four ramekins, stopping about a centimeter from the top. Scoop on the sweet potato topping and even it out slightly. You can do the traditional thing by smoothing the topping and then running the tines of a fork through it to make grooves.
Brush on the chili-garlic oil on the tops. Place the ramekins on a baking sheet and bake for 20-25 minutes or until the tops are slightly golden.