Heat the oil in a large pot or Dutch oven over medium heat. Add the chopped onion and sauté until translucent. Push the onion to the outside edges of the pan, then add the cubed chicken to the middle of the pot and cook until the chicken is no longer pink on the outside.
Add the chicken broth, creamed corn, frozen corn kernels, diced carrot, diced potato, ground thyme, garlic powder, salt, oregano, pepper, and bay leaf. Stir to combine.
Increase the stovetop heat to medium-high, bring the soup to a boil, then reduce the stovetop heat to low. Cover the pot with a lid and allow the soup to simmer for 15 minutes, or until the chicken is fully cooked and the vegetables are tender.
Stir in heavy cream. Allow the soup to simmer for an additional 1-2 minute(s).
Carefully remove the bay leaf from the pot, then stir in the lemon juice. Taste the soup, and add additional lemon juice, salt, or pepper based on taste preferences.
Ladle the soup into bowls, garnish with chopped parsley, then serve.