Place a large saucepan or dutch oven on the stove over medium heat.
Once hot, add the butter and melt. Add chicken cubes and cook until golden brown.
Next, add dried herbs and seasoning: Italian seasoning, oregano, thyme, pepper flakes, salt and pepper. Stir to combine and cook for 2 minutes, stirring.
Add diced onion and garlic, cook for about 3 minutes, stirring occasionally, until the onion is tender and translucent.
Add the rest of the veggies: bell pepper, celery, carrots, canned tomatoes, and sun-dried tomatoes.
Then, add the chicken broth and cream, stir to combine.
On medium heat, bring to a boil, reduce heat to low, cover and simmer for 10 minutes, stirring occasionally.
Add the cheese tortellini, stir and cook until tender on low-medium heat. Stir occasionally. Taste and adjust for salt and pepper.
If the soup is too thin for your liking and you would prefer a thicker broth, mix in a small bowl or cup the cornstarch with the water until fully combined and add the mixture to the soup with the tortellini.
Also, if the soup is still too thin, add another round of cornstarch slurry and simmer for 5 more minutes on low heat. Careful as the soup will thicken more once it starts to cool.
Once the tortellini are cooked, reduce heat to low and fold in fresh spinach. Fully submerge it under the liquid and gently stir. Cook just for a few minutes, until spinach is wilted.
Remove soup from heat and serve garnished with chopped fresh parsley.