Prep your produce. Slice the peppers and onion into thin strips.
Mince the garlic. Rinse and drain the black beans if using canned.
Mix the spice blend. In a small bowl, combine chili powder, cumin, smoked paprika, oregano, garlic powder, onion powder, 1 teaspoon salt, and 1/2 teaspoon black pepper.
Layer the slow cooker. Add peppers, onion, garlic, tomatoes, tomato paste, corn, and black beans to the slow cooker. Drizzle with olive oil.
Sprinkle half of the spice blend over the veggies.
Add the chicken and broth. Nestle chicken breasts or thighs on top. Sprinkle with the remaining spice blend. Pour in the chicken broth around the sides.
Cook low and slow. Cover and cook on Low for 6–7 hours or High for 3–4 hours, until the chicken is tender and easily shreds.
Shred the chicken. Remove the chicken to a plate and shred with two forks.
Return it to the pot and stir well.
Brighten and taste. Stir in the juice of 1 lime. Taste and adjust seasoning with more salt, pepper, or lime as needed.
Garnish and serve. Ladle into bowls and top with cilantro, a spoon of Greek yogurt, a sprinkle of cheese, avocado slices, or crushed tortilla chips for crunch.