Preheat oven to 350°.

In a small saucepan bring one and a half cups water to a boil. Place quinoa in a strainer and rinse under cold running water until the water runs clear. Stir the quinoa into the boiling water cover and simmer until the quinoa is tender and water is absorbed about 15 minutes. Let stand covered for five minutes. Float fluff with a fork and set aside.

Meanwhile use a sharp knife to cut out the core from the peppers. Pull out any seeds in rinse the peppers inside and out. Place them cut side down on the microwave-safe plate. Microwave on high power until slightly softened 3 to 4 minutes. Set aside to cool.

In a large skillet heat oil over medium heat. Add onion mushrooms garlic and crushed red pepper if using. Continue to cook stirring occasionally until the mushrooms are golden brown about eight minutes.

Stir in tomato paste and cook for one minute. Stir in zucchini tomatoes oregano and salt and pepper and cook for about two minutes. Stir in the quinoa and remove the pan from the heat.

Place the peppers cut side down in a medium roasting pan. Spoon filling into the peppers and fill the pan with water half inch deep. Bake until the peppers are tender and the top of the filling is slightly brown and crunchy about 30 minutes.

Meanwhile in a small sauce pan heat the marinara over low heat. When the peppers are cooked place one on each of four plates. Spoon the sauce on side or on top and serve.