Slow Cooker Creamy Tortellini Soup

| 1 pound ground Italian sausage ((or ground chicken, turkey or beef), browned*)

brown onion (, chopped)

large carrots (, chopped)

stalks celery (, chopped)

garlic (, minced)

Italian seasoning

beef bouillon powder ((or chicken))

salt

beef broth ((or chicken or vegetable broth -- I use low sodium))

cornstarch mixed and dissolved in 1/4 cup water

x 340 gram | 12-ounce cans full fat evaporated milk or half and half

x 340 gram | 12 ounce packet three cheese tortellini ((I used dried not fresh; choose any flavour you like))

fresh baby spinach

milk