Start by heating 2 tablespoons of olive oil in a large pot over medium heat. Once the oil shimmers, add the boneless, skinless chicken breasts or thighs, searing them for 3 to 4 minutes until golden brown on one side. Flip the chicken and cook for an additional 3 to 4 minutes, ensuring it's browned on both sides. Remove the chicken and set it aside on a plate.

In the same pot, add the diced onion and minced garlic, stirring for about 2 to 3 minutes until the onion becomes translucent and fragrant. If you’re opting for added veggies, toss in some diced celery and carrot at this stage, cooking for another 2 minutes until slightly softened.

Next, stir in 1 cup of sun-dried tomatoes with their oil, allowing them to mingle with the aromatics for about 1 to 2 minutes.

Pour in approximately 4 cups of warm chicken stock, and carefully return the seared chicken to the pot. Bring the mixture to a gentle simmer over medium heat. Cover and let it cook for 15 to 20 minutes, or until the chicken is fully cooked through and tender.

Once the chicken is cooked, remove it from the pot and shred it using two forks. Return the shredded chicken back to the pot.

Reduce the heat to low before stirring in 1 cup of heavy cream and ½ cup of grated Parmesan cheese. Mix gently until the cheese has melted and the soup becomes creamy and smooth.

Now, sprinkle in a tablespoon of fresh thyme and a pinch of red pepper flakes, stirring for another minute to blend the flavors.

Before serving, taste your soup and adjust the seasoning as necessary. Ladle the creamy soup into bowls and garnish with fresh basil leaves and extra Parmesan cheese.