Prepare your mise en place. Dice the onion, carrots, celery, and red bell pepper. Mince the garlic. Pat the chicken breasts dry with paper towels and set aside the heavy cream and chopped spinach.

Heat the olive oil in a large pot over medium heat until shimmering but not smoking. Add the diced onion and minced garlic and sauté for 2–3 minutes until the onion becomes translucent.

Add the diced carrots, celery, and red bell pepper to the pot. Cook for about 5 minutes until the vegetables begin to soften.

Nestle the chicken breasts into the pot, pour in the chicken broth, and sprinkle in the dried Italian herbs. Bring to a gentle boil and then reduce to a low simmer.

Simmer uncovered for 20 minutes or until the chicken is cooked through and registers 165°F on an instant-read thermometer.

Remove the chicken breasts from the pot and shred them into bite-sized pieces before returning them to the pot.

Stir in the heavy cream and add the chopped spinach, cooking for another 2–3 minutes until the spinach wilts.

Taste and season with salt and freshly ground black pepper to your preference. Optionally, add a squeeze of lemon for brightness.

Ladle the soup into warmed bowls and finish with freshly grated Parmesan cheese. Serve hot.