Season the chicken with salt and pepper from both sides.
In a dutch oven, heat oil and brown the chicken from both sides (2-3 minutes per side), then remove onto a plate.
To the dutch oven, add onion and cook for 3 minutes or until it’s soft and translucent (keep stirring every 30 seconds with a spatula). Add garlic, and cook for 30 seconds, then add chili powder, smoked paprika, cumin, onion powder, and dried oregano. Stir and cook for 30 more seconds. Add red enchilada sauce, and scrape the bottom of the pot with a wooden spoon.
Add black beans, corn, fire-roasted diced tomatoes with chilies, chicken stock.
Return the chicken. Stir and bring to a boil, then partially cover with a lid and allow to simmer for 10-15 minutes or until the internal temp of the chicken is 165°F/74°C.
Remove the chicken from the soup, and shred with 2 forks.
Add cream cheese and 1 cup of cheddar, and mix until the cheeses melt. Return the chicken to the soup, and remove it from heat.
Optionally, you can thicken the soup more by stirring in a slurry of cornstarch and water.
Serve in bowls, sprinkle with remaining cheddar cheese, sour cream, chopped cilantro, and tortilla chips.