Using a large heavy-bottomed pot or Dutch oven, heat the olive oil over medium-high heat. Add the onion and cook until translucent, for about 4 to 5 minutes. Add the garlic and cook for 30 seconds. Add the diced zucchini and the bell peppers and season with the cumin, oregano, chili powder, and season with salt and pepper. Cook, stirring frequently, for about 4 to 5 minutes. Add the beans, Swiss chard, corn, and chicken stock.