Begin by heating the olive oil in a large pot over medium heat. Allow the oil to warm for about a minute.
Add the finely diced onion to the pot and sauté it for approximately 5 minutes, or until it becomes translucent and fragrant.
Next, stir in the minced garlic along with the diced carrots and celery. Cook the mixture for an additional 3-4 minutes, stirring occasionally, until the vegetables start to soften.
Pour in the 4 cups of chicken broth, and bring the mixture to a rolling boil.
Once boiling, add the shredded chicken, frozen peas, dried basil, and dried oregano. Stir everything together until well combined.
When the soup returns to a rapid boil, reduce the heat slightly. Add the cheese tortellini and cook according to the package instructions (typically 3-5 minutes), or until the tortellini float to the surface, indicating they are cooked through.
Taste the soup and season with salt and freshly ground black pepper as desired.
After adjusting the seasoning, remove the pot from heat and let the soup rest for a few minutes to cool slightly and develop the flavors.
To serve, ladle the hot soup into bowls and generously garnish with freshly chopped parsley on top.
Notes
For an added touch, serve the soup with a slice of crusty bread or a sprinkle of grated Parmesan cheese for extra flavor.