Brown the Turkey: In a skillet over medium heat, add 1.5 lbs ground turkey. Cook until it's browned, about 5 minutes. Add 1 large sweet onion, chopped halfway through the process, stirring until both the turkey and onion are soft. Lastly, stir in 2 cloves minced garlic for another minute until fragrant. Drain any excess grease and transfer the mixture to your crockpot.
Prepare the Broth Mixture: In a mixing bowl, whisk together 3 cups low-sodium chicken broth and 6 oz tomato paste. After combining, pour this mixture over the turkey and onion mix in the crockpot.
Add Tomatoes and Beans: Next, add 20 oz diced tomatoes with green chilies, 14.5 oz fire-roasted diced tomatoes, 15.5 oz dark red kidney beans, rinsed, and 15.5 oz pinto beans, rinsed into the crockpot. Stir to combine evenly.
Season the Chili: Add 3 tbsp chili powder, 2 tsp ground cumin, 1 tsp smoked paprika, and 1 tbsp brown sugar to the mix. Season with red pepper flakes & cayenne to taste, as well as salt & pepper to taste. Mix until everything is well incorporated.
Cook: Cover the crockpot and cook on low for 6-8 hours or on high for 3-4 hours. The chili is ready when it's thick and the flavors are rich and developed. Stir occasionally if possible.