Heat olive oil in a large pot or Dutch oven over medium-high heat. Add chicken and cook until browned on all sides. Remove chicken from pot and set aside.
Add onion, carrots, and celery to the pot. Cook, stirring occasionally, until softened, about 5-7 minutes.
Stir in minced garlic and cook for 1 minute more until fragrant.
Pour in chicken broth and add Italian seasoning, salt, and pepper. Bring to a boil.
Reduce heat to low, cover, and simmer for 10 minutes to allow flavors to meld.
Add the cooked chicken and refrigerated tortellini to the pot.
Cook for another 5-7 minutes, or until tortellini is tender and cooked through.
Stir in frozen peas and cook for 1-2 minutes until heated through.
Ladle soup into bowls and garnish with fresh parsley.
Notes
You can substitute chicken thighs for chicken breasts if desired.
Feel free to add other vegetables like spinach, corn, or diced tomatoes.
For a creamier soup, stir in 1/2 cup of heavy cream or half-and-half during the last few minutes of cooking.