In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until translucent.
Add the garlic, bell pepper, carrots, and celery to the pot. Cook for an additional 5-7 minutes, stirring occasionally, until the vegetables are softened.
Stir in the black beans, chickpeas, diced tomatoes (with juice), vegetable broth, chili powder, cumin, smoked paprika, salt, and pepper. Bring the mixture to a boil.
Reduce the heat to low and let the chili simmer for 20-30 minutes, stirring occasionally. If the chili is too thick, add more vegetable broth as needed.
Taste and adjust seasoning if necessary. Serve hot, garnished with fresh cilantro, avocado, and lime wedges if desired.