1. Preheat the oven to 350 degrees F. Prepare the quinoa according to the package
2. While the quinoa is cooking, wrap the peppers in aluminum foil, and bake in the oven until tender, but not falling apart, about 15 minutes.
3. Remove from the oven and allow to cool slightly while you prepare the filling.
4. In a large skillet over medium-high heat, brown the turkey. After turkey is browned, drain. Add meat back to pan and add oil. Add the onions, mushrooms and garlic to the pan and sauté until the mushrooms are golden brown. Add in the zucchini, yellow squash, quinoa, tomatoes, and red pepper and continue to cook until the vegetables are tender. Add the salt, pepper and Italian seasoning. Adjust the seasoning with salt and pepper, to taste, and stir in the tomato paste. Remove from the heat.
5. Spoon the vegetable mixture into the cooled peppers. Transfer the peppers to a heat-proof serving dish and top each with Parmesan. Bake until the peppers are heated through, about 15 minutes.