Heat a large stockpot to medium high heat. While it gets hot, mix together the spices (paprika, cumin, garlic powder, sea salt) and add to the cut up chicken pieces.
Make sure the pot is HOT. Now add 1 tbsp oil, then add the spiced chicken. Cook on each side until the chicken is browned/blackened, don't flip over or stir the chicken for at least 3-4 minutes. It should take the chicken about 8 minutes or so. Remove the chicken from the pot, but keep the pot hot and don't clean.
Add another tbsp of oil if needed. Now add the diced green onion, bell pepper, and 1/4 cup of the cilantro. Sauté for about 4-5 minutes, stirring and making sure to get some of the browned spices scraped up from the bottom of the pot.
Once veggies are softened, add the lime juice, tomatoes, broth, and bring the chicken back to the pot. Increase the heat to a boil for about 2 minutes, then reduce to low. Let simmer for 8-10 minutes.
Dice up the avocado. Serve hot with remaining cilantro and top with avocado.