Pat the turkey breast dry. Combine the 4 spices with 1 1/4 tsp salt and 3/4 tsp of pepper. Season the turkey breast all over with the spices.
Place onion and celery in the bottom of the slow cooker, and add the chicken stock and the wine. Place turkey, breast side up, on top of vegetables. Cook on low for 4 hours or until the internal temperature is 165 degrees. Remove turkey from slow cooker and let rest for 15-20 minutes.
Strain slow cooker liquid through a fine mesh strainer. Discard solids.
Melt the butter in a medium saucepan. Whisk in flour and cook about 3 minutes stirring constantly, to form a roux. Gradually whisk in pan drippings. Bring to a boil and then reduce heat. Simmer, whisking constantly, until gravy has thickened, 5-10 minutes. Taste and season gravy with more salt and pepper if needed.
Slice turkey and serve immediately with gravy.
Enjoy!