In a large skillet over medium heat, brown 1 ½ pounds of ground beef for about 5-7 minutes until it's no longer pink. Halfway through, add 1 large chopped sweet onion, cooking until softened and translucent. Once browned, drain any excess grease.

Stir in 2 minced garlic cloves and sauté for an additional minute, allowing the garlic to become fragrant.

Transfer the beef mixture to your crockpot. Pour in 3 cups of low-sodium beef broth, 1 can of tomato paste, and 2 cans of diced tomatoes with green chilies, followed by 1 can of fire-roasted diced tomatoes.

Drain and rinse 1 can each of dark red kidney beans and pinto beans, then add them to the crockpot. Next, mix in 3 tablespoons of chili powder, 2 teaspoons of ground cumin, 1 teaspoon of smoked paprika, and 1 tablespoon of brown sugar. Sprinkle in red pepper flakes and cayenne.

Gently stir all ingredients together in the crockpot until well combined. Cover and set to cook on low for 6-8 hours or high for 3-4 hours.

Once the cooking time is up, taste the chili and season with kosher salt and black pepper to your preference.