Slow Cooker White Bean Basil Chicken Soup

small onion, chopped

stalks celery, chopped

garlic

diced tomatoes

white beans (drained)

chicken breasts (you can use frozen)

dried basil

salt

⁄2 tsp. white pepper

⁄4 tsp. crushed red pepper flakes (optional)

chicken stock

sundried tomatoes (optional)

Parmesan cheese, shaved

chopped red onion (for garnish)