In a dutch oven or large stockpot, melt the butter over medium heat. Add the carrot, celery, and onion, stirring occasionally until softened and slightly browned, 10 minutes. Add the garlic, cook for 30 seconds until fragrant, stirring constantly.
Add the flour to the pot and mix it in, cook for 1 minute.
Pour in the stock and add the potatoes. Season with the bay leaf, thyme, and pepper, stir it until mixed.
Bring to a boil reduce the heat to low and simmer for 15 minutes or until the potatoes are tender. Stir occasionally to make sure nothing sticks to the bottom of the pan.
Add the cooked chicken, heavy cream, peas, and corn, stir to combine.
Bring back to a simmer and simmer for 5 minutes until everything is warmed. Discard the bay leaf. Serve with biscuits and a garnish of fresh parsley, optional.
This can be frozen, see my tips above.
Heavy cream can be substituted with half and half or milk.
You can add other vegetables to this if you like, see my tips above.
The biscuits are optional but great to serve with this soup.