Add the chicken, tomatoes, and jalapenos to a 5 or 6 quart slow cooker.
In a large saucepan, melt the butter over medium heat. Once melted, add the garlic and saute until fragrant, about 30 seconds. Add the chili powder and cumin and cook another minute. Stir in all the chicken broth and bring to a boil.
Remove from heat and stir in the salt and pepper, and the glucomannan if using, to thicken the sauce. Pour over the chicken in the slow cooker.
Set the slow cooker to high for 3 hours or low for 6 hours.
When the time is up, remove the chicken to a plate. Add the shredded cheese and the cream cheese to the slow cooker and replace the lid. Let melt 10 minutes, then use an immersion blender to blend everything together.
Shred the chicken with two forks and stir back into the soup. Serve hot with chopped tomatoes, cilantro, and additional cheese, as desired.