Heat a large soup pot over medium heat and add the butter.
While the butter is melting, dice the onion and add it to the butter.
Shred the carrots and potatoes.
Once the onion is translucent, add the carrots and potatoes to the pot. If there isn't enough butter to generously coat the veggies, add a little more. Add a little salt and pepper. Cook for 2-3 minutes stirring fairly often.
Pour in the chicken broth and scrape the bottom of the pan with your wooden spoon to get up any browned bits from the veggies.
Add in the poultry seasoning, thyme, and some salt and pepper.
Dice the chicken breasts into bite-size pieces and add to the broth.
Simmer until the chicken is cooked, about 10 minutes.
Remove the soup from the heat and stir in the milk and the frozen corn. Let the soup sit for about 5-10 minutes until the corn is warmed through.