Begin by dicing the yellow onion, red bell pepper, and chopping the carrots and celery into small, uniform pieces. Place these vegetables directly into your slow cooker; they will form the hearty base of your Crockpot Vegetarian Chili. Mix them gently until they are well combined and showcase a colorful medley.

Pour the tomato sauce and diced fire-roasted tomatoes over the mixed vegetables in the slow cooker. Use a wooden spoon to stir everything together, ensuring the vegetables are well-saturated with the flavorful liquids. This step sets the foundation for a rich chili base that will develop throughout the cooking process.

Rinse and drain the black beans, kidney beans, and pinto beans in a colander. Gently fold these beans into the slow cooker, mixing them into the tomato mixture and vegetable base. Their creamy texture will enhance the overall body of your Crockpot Vegetarian Chili, adding both heartiness and nutrition.

Sprinkle in the kosher salt, granulated garlic powder, ground cumin, mild chili powder, and smoked paprika. Stir thoroughly to evenly distribute the spices throughout the chili. As the aromas begin to mingle, you'll see the ingredients coming together to create a tantalizing flavor profile that will enhance your cooking experience.

Cover your slow cooker with a lid and set it to cook on high for 4-5 hours or on low for 6-7 hours. You’ll know it’s ready when the vegetables are tender, and the chili has thickened to a delightful stew-like consistency. The enticing scents wafting from the cooker will make the wait worthwhile.

Once cooked, stir in the fresh lime juice and adjust the flavor with hot sauce if you desire a bit of heat. This brightens the dish and adds a fresh kick that elevates your Crockpot Vegetarian Chili to the next level.

Before serving, take a moment to taste your chili and adjust the seasoning to your preference. If it needs more salt or spice, this is the ideal time to make those tweaks. A well-balanced flavor will ensure each bowl is as satisfying as possible!