In a large skillet over medium heat, melt margarine. Add sliced mushrooms and chopped green onions. Cook, stirring occasionally, until soft, about 15 minutes. Add unchicken broth and bring to a boil. Stir in quinoa and chopped broccoli. Reduce the heat, cover, and simmer until the quinoa is tender, about 15 minutes. Sprinkle with nutritional yeast and serve warm.