In a slow cooker, mix together the potatoes, onion, celery, garlic, thyme, chicken stock, and spices. Cover with lid and cook on low for 6-8 hours or until the potatoes become tender.
In a small bowl combine the evaporated milk with the cornstarch, add to the slow cooker along with the cream cheese cubes, cover and cook on high for 30-40 minutes, until the broth thickens.