Heat a large pot over medium heat and add a splash of oil.
Sauté the diced onion and bell pepper until they soften, about 5 minutes.
Add the minced garlic and cook for another minute until fragrant.
Stir in the chili powder and cumin, cooking for an additional minute.
Add the diced tomatoes, black beans, kidney beans, and corn.
Pour in the vegetable broth, stirring to combine.
Bring the mixture to a boil, then reduce heat and let it simmer for 20 minutes.
Season with salt and pepper to taste.
Allow the chili to sit for a few minutes before serving.
Serve hot, garnished with fresh cilantro if desired.