Prepare chicken by cooking and shredding after letting it cool. This can be prepared ahead of time.
In a largepot, melt the butter over medium-high heat. Add the onion and cook for a few minute until fragrant. Add the shredded chicken, chicken broth, diced tomatoes, tomato paste, chili powder, cumin, garlic powder, and jalapeno to the pot and combine gently. Bring to a boil, then drop it down to a simmer over medium-low heat and cover for 10 minutes.
Cut cream cheese into small, 1-inch chunks.
Remove lid and mix in the cream cheese. Increase the heat back up to medium-high and continue to stir until the cream cheese is completely blended in. Remove from heat and season with salt and pepper to taste.