Sauté the Aromatics
Heat olive oil in a large pot over medium heat. Add onion, carrots, and celery. Cook for 5–6 minutes until softened. Add garlic and cook 30 seconds more.
Add Chicken and Broth
Place whole chicken breasts into the pot. Pour in chicken broth and add Italian seasoning. Bring to a gentle boil, then reduce to a simmer. Cook 15–18 minutes.
Do not boil aggressively — gentle simmer keeps chicken tender.
Shred the Chicken
Remove chicken and shred with two forks. Return it to the pot.
Let it rest 5 minutes before shredding to keep juices inside.
Cook the Pasta
Add pasta directly into the simmering soup. Cook 8–10 minutes until al dente. Stir occasionally to prevent sticking.
Do not overcook the pasta — it continues softening in the hot broth.
Add Spinach
Stir in chopped spinach during the last 2 minutes of cooking. It wilts quickly and keeps its bright color.
Final Seasoning
Taste and adjust salt and pepper. Add Parmesan if using. Serve hot.