Heat the olive oil in a large soup pot or dutch oven over medium heat.
Add in the diced onion, carrots, celery, bell pepper, and garlic. Season with a pinch of salt and pepper.
Cook, stirring occasionally, until the veggies become slightly soft, around 3-4 minutes.
Add in the oregano, paprika, thyme, and Italian seasoning and continue cooking until the spices become fragrant, about 1-2 minutes.
Pour in the chicken broth and tomato sauce and increase the heat to high.
Bring the soup to a boil and add the pearl barley.
Immediately decrease the heat to medium and cover with a lid. Let the soup siimmer until the barley is cooked through, about 45-65 minutes depending on the barley.
Uncover and add the turkey, baby spinach, and fresh parsley. Stir to combine and continue cooking until the turkey is heated through and the parsley is wilted, about 6-8 minutes.
Taste and adjust the seasoning with salt and pepper, if desired.