2 lb sweet potatoes/yams
1 qt vegetable or chicken stock
1 qt milk (not skim; or more stock and some heavy cream)
1 small onion
1 large orange
1 stick cinnamon
1 T fresh grated or  1/2 tsp. ground ginger
1/2 tsp ground nutmeg (preferably fresh)
1/2 stick butter
salt & pepper

You will need a food processor.

In a large soup or stock pot, melt the butter and add the onion diced finely. When near translucent, add the peeled & chopped (coursely, about the size of brussel sprouts) potatoes, add salt & pepper. Allow to brighten in the butter; when begins to be dry, add enough stock to almost cover, and add the spices. Add lid and reduce heat to just above low. Let them simmer and steam for about 20 minutes, checking to make sure they have enough liquid and adding some water or stock in the process. Halfway through, add the zest and juice of the orange.

Once brightened and easy to smash with a wooden spoon, turn off heat, remove cinnamon stick, and add to food processor, pureeing. Add back to the pan and begin adjusting consistency and strongness of flavor with the milk and stock. The bisque should be lighter and runny but retain its color. If it’s too thick you’ll be way too full and it will seem too sweet. If it’s too sweet and you’re using fresh ginger, feel free to add a bit more as well as more milk (NOT stock as milk will mellow the flavor better than the stock).

Will store well in the freezer or fridge for some time. Serve with Creme Fraiche and chives or a slice of fresh or candied orange & a crack of pepper.