1. Heat the olive oil in a large pot or Dutch oven over medium-high heat. Add the chicken pieces and cook until browned on all sides, about 5-7 minutes. The chicken doesn’t need to be cooked through at this stage, just nicely seared for flavor. Remove the chicken from the pot and set aside.

2. Reduce the heat to medium. Add the chopped celery and onion to the pot, scraping up any browned bits from the chicken. Cook, stirring occasionally, until the vegetables are softened, about 5-7 minutes. They should become translucent and fragrant.

3. Stir in the minced garlic, dried thyme, and dried rosemary. Cook for another minute until the garlic is fragrant. Be careful not to burn the garlic.

4. Pour in the chicken broth, bringing it to a gentle simmer. Return the browned chicken to the pot. Cover and let it simmer for 10-12 minutes, or until the chicken is cooked through and tender.

5. Reduce the heat to low. Stir in the heavy cream and fresh spinach. Cook for 2-3 minutes, just until the spinach wilts and the soup is heated through. Do not boil the soup once the cream is added, as it can curdle.

6. Remove the pot from the heat. Stir in the fresh parsley. Taste the soup and season generously with salt and black pepper as needed. The flavors will deepen as it sits.

7. Ladle the hearty keto chicken soup into bowls. If desired, sprinkle with grated Parmesan cheese before serving. Enjoy immediately!