Sunchoke Soup with Persimmon

1 cup Yellow onions, small dice
6 tbl butter
1 cup leeks, white only small dice
2 qts sunchokes, peeled, uniform cut
2 qt chicken stock
1 cup heavy cream
3 thyme sprigs
1 ea bay leaf
2 clove garlic
kosher salt

1. sweat onion and leeks in the butter until tender. season with salt and add garlic. Sauté 1 min
2. add the sunchokes and chicken stock. Bring to a boil simmer till sunchokes are tender
3. puree and pass through strainer
4. add cream and buttermilk, adjust seasoning and serve
5. Garnish with persimmon and herbs

Notes: Hold back some of the stock when pureeing in blender to adjust final thickness.
If you want a thick soup use less stock and for thinner soup use more stock.
Another variable is the starchiness of the sunchoke.