Cook quinoa according to package instructions; set aside.
Heat olive oil in a Dutch oven or large pot over medium high heat. Add garlic and onion, and cook, stirring frequently, until onions have become translucent, about 2-3 minutes.
Stir in cooked quinoa,crushed tomatoes, tomato sauce, chili powder, cumin, chili powder and 1 cup water or vegetable broth, making sure to cover most of the ingredients; season with salt and pepper, to taste.
Reduce heat to low; simmer, covered, until thickened, about 30 minutes. Stir in beans and corn and cook until heated through, about 2 minutes.
Serve immediately with avocado, cheese, or greek yogurt if desired.