In a large Dutch oven, heat olive oil over medium-high heat. Season chicken thighs with salt and pepper, then sear for about 5-7 minutes on each side until golden brown. Remove chicken and set aside.

Lower the heat to medium, add unsalted butter, then toss in chopped onion, diced carrots, and diced celery. Sauté for 5-6 minutes until vegetables are tender.

Stir in minced garlic and cook for 1 minute. Sprinkle in all-purpose flour, stirring constantly for about 2 minutes. This will slightly cook the flour.

Slowly pour in chicken broth while stirring to avoid lumps. Add back the seared chicken and granulated chicken bouillon. Bring to a simmer over medium heat.

Once chicken is tender, about 15 minutes later, shred it using two forks and return to the soup.

Whisk together half and half with cornstarch until smooth. Gradually stir into the soup, then add uncooked noodles. Cook noodles for about 8-10 minutes until tender.

Stir in Parmesan cheese, let melt into the soup, and taste to adjust seasoning. Remove from heat and let sit before serving.