Mix Spice Blend:
Mix together the chili powder, mustard powder, garlic powder, onion powder, cumin, cinnamon, and cayenne pepper; reserve. Remove cream cheese from fridge to soften. Grate cheddar and Monterey Jack from a block and set aside.Sauté Aromatics:
In a large soup pot over medium heat, warm the butter and olive oil. Sauté the diced onion and jalapeno for 4 minutes until softened, then add minced garlic and cook an additional 1 minute.Season and Add Chicken:
Dry the chicken breast with paper towels and season both sides with salt and pepper. Place it into the pot with all remaining ingredients except the cream cheese and shredded cheeses.Cook and Shred Chicken:
Bring the soup to a low boil and let the chicken cook gently until done, about 15-20 minutes (avoid rapid boiling to prevent toughness). Remove the chicken, shred using two forks, and return the shredded meat to the pot.Melt Cheeses:
Lower the heat to low. Incorporate the softened cream cheese, stirring until smooth, then add the shredded cheeses and stir until fully melted.Adjust and Serve:
Adjust seasoning if needed, then serve.