Preheat oven to 400. Chop the top off the garlic and peel away the loose outside paper. Drizzle olive oil on cloves, wrap in foil and roast for 20-30 minutes, or until golden. Let cool.
Cook quinoa according to directions on package. While quinoa is cooking, heat a skillet on medium heat and add olive oil. Add red pepper and mushrooms and saute until soft, about 6-8 minutes. When quinoa is done, fluff with a fork and add peppers and mushrooms. Squeeze the entire head of garlic cloves into the quinoa, mashing some with a fork and leaving others whole. Season with salt and pepper and mix well.