Set a large dutch oven or soup pot over medium-high heat. Add bacon and cook until it has rendered its fat and is crispy.
Remove bacon and strain it onto a paper towel-lined plate, and set aside.
Leave the bacon grease in the pot and add chicken to the pot. Cook until no longer pink.
Add in the onions, celery, red bell peppers, and potatoes and saute for about 5 minutes.
Add in the garlic and saute for 30 seconds.
Add in the thyme leaves and flour. Stir to coat all the vegetables in flour.
Stir in a little chicken stock, stir to help incorporate the flour and slowly stir in the rest of the stock. Stir to combine.
Add the corn and half and half, stir to combine, and let simmer for about 20 minutes or until warmed and slightly thickened. (This soup is not super thick!)
Stir in the black pepper, taste, and add kosher salt as needed.
To serve, ladle the soup into bowls and top with some of the crispy bacon and sliced green onions.