Preheat a medium skillet over low flame and sauté the onion with a splash of water until translucent, about 5 minutes.
Stir in the chopped mushrooms and toss to coat. Cook another 5 minutes or so until they release all the moisture.
Stir in the onion powder, paprika, garlic, nutritional yeast and thyme then add the wine or vegetable stock. Cook until the wine has evaporated and your filling is on the dry side.
Add the quinoa + 2 tablespoons of marinara sauce to the mushrooms and mix to combine. Adjust seasonings to taste with sea salt and black pepper.
Meanwhile cut the bell peppers in half lengthwise and discard the core and seeds.
Fill each pepper half with the mushroom mixture. You should have just enough for the 6 halves.
Spread half of the tomato sauce on the bottom of a pan and top with the stuffed peppers. Spoon the remaining sauce over the top of the peppers. Optional: top each pepper with half of a slice of the vegan cheese.
Cover the pan with aluminum foil (an oven proof lid or a larger pan) and bake in the preheated oven for 1 hour.
Serve garnished with the chives, parsley or micro greens and a drizzle of cashew aioli.