Add the olive oil and onion to a Dutch oven or soup pot and sauté over medium-high heat until softened and lightly browned (about 5-7 minutes).
Add the remaining soup ingredients to the pot except for the cream cheese, chicken, and salt & pepper.
Increase the heat to high and bring the soup to a boil. Reduce the heat so it's simmering gently (uncovered) for 5 minutes.
Cut the cream cheese into smaller pieces and microwave it in 20-30 second intervals until very soft, then add it to the soup. Let it melt in (you may have to stir it a fair bit until it's fully dissolved).
Stir in the chicken and cook for another 5-7 minutes or so.
Season the soup with salt & pepper and serve with toppings as desired.
