Heat the olive oil in a large pot over medium heat. Add the onions, garlic, and carrots. Cook until softened, about 8 to 10 minutes.
Add the Italian seasoning, crushed red pepper, diced tomatoes, chicken stock, salt and pepper. Simmer the soup for about 10 minutes.
Add the tortellini to the soup and simmer until the tortellini is cooked, about 3 to 5 minutes. Add the fresh herbs and stir to combine. To serve, ladle the soup into bowls and garnish with grated Parmesan.
Notes
You can use refrigerated tortellini for this soup, but you may need to adjust the cooking time. Frozen tortellini cooks much faster - the refrigerated tortellini may need several more minutes. Please see the recommendations in the post about how to store the leftovers or if you want to make this soup ahead. The pasta does not keep well in the soup - it will absorb all the liquid.Nutrition information does not include the Parmesan cheese garnish.