On the stove top, In a large pot, heat the olive oil over medium-high heat. Add the onion and sauté until translucent and fragrant.
Add garlic and Thyme and cook for 2 minutes longer.
Pour in the broth and bring the soup to a boil.
Reduce to a simmer and carefully place the chicken breast with the broth. Cook the chicken breasts for about 10 – 15 minutes or until no longer pink on the inside.
Remove the chicken breasts from the pot and set them aside on a plate.
Keep the soup simmering and add the tortellini and cook for 7-8 minutes until the tortellini is tender.
Carefully chop or shred the chicken breasts and add them into the soup pot along with the spinach and fresh lemon juice. Start with two tablespoons, give it a taste, and then add more if you prefer.
Continue cooking until the soup is hot—season with salt and pepper.
Serve hot with grated parmesan cheese.