Sauté the Vegetables: Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion, bell peppers, and carrots. Sauté for 5-7 minutes until the vegetables start to soften.

1. Add Garlic and Zucchini: Add the minced garlic and chopped zucchini to the pot and cook for another 2-3 minutes, stirring frequently, until the zucchini softens.
2. Add the Beans and Tomatoes: Stir in the diced tomatoes (with their juices), kidney beans, black beans, corn, and tomato paste. Mix everything well.
3. Season the Chili: Add the chili powder, cumin, smoked paprika, cayenne pepper (if using), salt, and pepper to the pot. Stir to evenly coat the vegetables and beans with the spices.
4. Add Broth and Simmer: Pour in the vegetable broth (or water), and bring the chili to a simmer. Reduce the heat to low and let it cook uncovered for 25-30 minutes, stirring occasionally, until the vegetables are tender and the flavors have melded together.
5. Finish and Adjust the Seasoning: Once the chili is done simmering, stir in the lime juice (if using) for a burst of freshness. Taste and adjust the seasoning as needed, adding more salt, pepper, or spices to your liking.
6. Serve: Ladle the chili into bowls and garnish with your favorite toppings, such as chopped cilantro, sliced avocado, sour cream, shredded cheese, or tortilla chips. Serve with cornbread or over rice for a complete meal.