Chop the onion and bell peppers into small, even pieces and mince the garlic. Prepare all ingredients for easy addition.
Pour the olive oil into a skillet and warm over medium heat. Add the chopped onion and peppers, sautéing until they become soft and slightly translucent, about 5 minutes. The vegetables will smell sweet and start to brown lightly.
Add the minced garlic to the skillet and cook for another 30 seconds, just until fragrant. Be careful not to burn it; you'll notice a fragrant aroma filling the kitchen.
Transfer the sautéed vegetables and garlic into the slow cooker. Add the rinsed black beans, diced tomatoes with their juices, chili powder, ground cumin, and smoked paprika. Stir everything well to combine.
Pour the vegetable broth into the slow cooker, ensuring the ingredients are mostly covered. Give everything a good stir to blend the flavors evenly.
Cover the slow cooker with the lid and set it to low. Let it cook for 6 to 8 hours. During this time, the flavors will meld, and the vegetables will become tender, with the chili thickening into a hearty stew.
When the cooking time is up, carefully remove the lid and give the chili a gentle stir. It should be thick, with vibrant colors, and aroma-filled.
Taste test the chili and adjust seasoning if needed, adding more salt, spices, or a dash of lime for brightness. Serve hot, garnished with your favorite toppings if desired.
