Place chicken, garlic, onion, carrots, celery, beans, and bay leaves into a large slow cooker. Season with salt and pepper to taste.
1½ pounds shredded rotisserie chicken, 3 cloves garlic, 1 yellow onion, 3 carrots, 3 ribs celery, 30 ounces Great Northern beans, 2 bay leaves, Kosher salt and freshly ground black pepper