Heat a large pot on medium heat and add olive oil. Add onions and peppers with a sprinkle of salt and saute until soft, about 6-8 minutes. Stir in spinach and garlic. Add butter, and once it melts whisk in flour to create a roux. Make sure you whisk all ingredients together.

Add chicken to the pot, along with milk and chicken stock. Allow soup to come to a simmer, then add brie and continue stirring until it all melts – about 5 minutes. Stir in half and half. Turn heat up high and let soup come to a boil, stirring every few minutes so cheese does not stick to the bottom. At this point, you may see some separate of stock/milk, but with a few stirs and time to simmer, the soup will come together.

Once soup boils, turn it down to a simmer and allow to cook for 25-30 minutes, stirring occasionally. Serve hot!