Wash and stem your mushrooms. You can remove the gills too, but I left them in because the stems were big enough.
Heat olive oil in a medium or large skillet over medium heat. Once heated, add peppers, zucchini and onions, and stir in seasonings. Cook until tender about 5-8 minutes.
Once vegetables are tender, add in the cup of cooked quinoa, diced tomatoes, and mozzarella.
Stir together on medium heat for about a minute.
Remove from heat, and use a spoon to scoop mixture into mushroom caps. Heap them so they are full.
Bake at 350 for 20 minutes, until mushrooms are cooked through.
