In a large soup pot, heat the oil on medium-high heat and then add the onion, bell peppers, & garlic; cooking & stirring each addition for about one minute before adding the next item.
Add in all the seasonings: chili powder, cumin, oregano, salt, cinnamon, & cayenne pepper. Cook and stir until it becomes fragrant, about 30 seconds.
Mix in the quinoa, beans, broth, & tomato sauce. Stir everything well then cover the pot with a lid and bring to a boil. Once the chili is boiling, reduce the heat to a simmer. Keep the chili on a slow simmer until the quinoa has thoroughly cooked, 20-30 minutes.
Before serving, add corn and season with more salt, to taste. If the chili is thicker than you prefer, add more broth. Add optional toppings to individual bowls & store leftover chili in an air-tight container in the fridge.