Heat olive oil in a large dutch oven or heavy-bottomed pot over medium-high heat.
Add onion and cook for 2-3 minutes until softened. Add garlic and green pepper and cook for an additional minute.
Pour chicken broth, diced tomatoes and taco seasoning into the pot. Bring to a boil.
Reduce heat to a simmer and add uncooked chicken breasts. Cook for 20-25 minutes or until the chicken reaches 165℉.
Remove chicken and shred it, once cool enough to handle. This can be done with two forks or a hand mixer.
To a blender add softened cream cheese and 1 cup of the soup. Blend until smooth.
Add the cream cheese mixture to the soup and whisk until fully incorporated. Stir in the shredded chicken. Taste and season with salt and pepper if desired.
Notes
Avoid adding the chicken too soon, as it will continue to cook in the final steps with the remaining ingredients.
Keep chicken taco soup refrigerated for up to 4 days and reheat on the stovetop.