Prep your veggies. Dice the onion and bell pepper, mince the garlic, and seed and chop the jalapeño if using. Smaller pieces soften better in the slow cooker.
Optional flavor boost: Sauté the onion, bell pepper, and garlic in a little olive oil over medium heat for 5–6 minutes until softened.
This step adds sweetness and depth but isn’t required.
Layer the base. Add the black beans, diced tomatoes, tomato paste, veggies, and green chiles or jalapeño to the slow cooker. Stir in the broth.
Season it. Sprinkle in chili powder, cumin, smoked paprika, oregano, salt, and pepper. If you like a deeper flavor, add the optional cocoa powder and a pinch of cayenne.
Nestle the chicken. Place the chicken breasts or thighs on top, pressing them down so they’re mostly submerged in the sauce.
Set and forget. Cook on Low for 6–8 hours or High for 3–4 hours, until the chicken is very tender.
Shred and finish. Remove the chicken to a board and shred with two forks.
Return it to the slow cooker. Stir in the lime juice and corn (if using). Taste and adjust salt, pepper, and heat.
Serve with toppings. Ladle into bowls and add your favorites: a dollop of sour cream, shredded cheese, chopped cilantro, sliced avocado, and a few crushed tortilla chips.