To roast the peppers, heat broiler to high. Cut peppers in half lengthwise. Throw out seeds and membranes. Place peppers skin side up on a foil-lined baking sheet. Flatten with hand. Broil 8 minutes or until roasted. Let cool. Coarsely chop peppers and place in a bowl.
To prepare the filling, start by cutting the zucchinis in half. Carefully scoop out each zucchini like a canoe, leaving shells intact. Chop the removed zucchini flesh.
On the foil-lined baking sheet, spread out the zucchini, corn and onion. Broil about 10 minutes, stirring twice. Then add to the bowl with chopped peppers. Stir in oregano, oil, lime juice, cumin and black pepper.
Preheat oven to 350 F.
Place quinoa in a fine sieve, and place sieve in a large bowl. Cover quinoa with water. Using your hands, rub the grains together for 30 seconds. Rinse and drain. Repeat this process twice.
In a medium saucepan, combine water, tomato sauce and quinoa. Bring to boil. Cover and reduce heat. Simmer for 15 minutes or until liquid is absorbed. Remove from heat. Fluff quinoa with a fork.
Add quinoa to zucchini and corn mixture. Toss well.
Spoon about 3/4 cup mixture into each zucchini shell. Sprinkle with cheese.
Bake for 20 minutes or until cheese is golden brown.