Heat the olive oil in a large Dutch oven over medium heat. Add the onion and the turkey Italian sausage and cook, stirring often, until the sausage has cooked through. Side Note: Use a potato masher to break up the Italian sausage quickly and easily into crumbles.
Add the carrot, celery, and minced garlic; stir often for 2 minutes.
Add the diced tomatoes, chicken broth, bay leaf, chicken bouillon granules, and season with sea salt and freshly cracked pepper, to taste. Cover with a lid and let the soup simmer for 1 1/2 hours, stirring occasionally.
Add the orzo and simmer for 15 minutes. Add the spinach right before serving. Taste and re-season if needed. Enjoy.