Preheat oven to 375°F (190°C).
Cook quinoa in vegetable broth according to package directions.
Heat 2 tablespoons olive oil in a large skillet over medium heat.
Add onion and cook until softened, about 5 minutes.
Add garlic and zucchini, cook for 3 minutes.
Add cherry tomatoes and corn, cook for 2 minutes.
Stir in cooked quinoa, pine nuts, herbs, salt, and pepper.
Brush bell peppers with remaining olive oil and place in a baking dish.
Fill peppers with quinoa mixture and top with nutritional yeast.
Cover with foil and bake for 35-40 minutes until peppers are tender.
Remove foil for last 10 minutes of cooking.