Finely chop one-fourth of the carrot and celery. Melt butter in a large pot, then add the garlic, and finely chopped carrot and celery. Saute vegetables over medium heat for 5 minutes.
Chop remaining carrots and celery, potato, and yam into medium pieces. Pour stock and remaining vegetables into pot. Simmer until vegetables are soft. Reduce heat and add Italian seasoning and black pepper to pot.
Wisk cream and flour together (water may be added to thin mixture). Slowly stir mixture into soup. Bring soup back to a simmer to thicken.
Add dried cranberries, chopped green beans, and turkey to pot, and continue cooking long enough to heat through.
Serve topped with stuffing.