Potato Soup with Lemons

Directions

1. 1
   In a saucepan over medium heat, melt the butter.
2. 2
   When it begins to foam, add the onions, lemon zest, and ginger and saute until the onions are translucent, about 10 min.
3. 3
   Add the lemon juice with sugar, salt and pepper; continue to saute for 2 to 3 min longer.
4. 4
   Add the water, raise the heat to high, and bring to a boil.
5. 5
   Cover, reduce the heat to medium, and simmer until the broth is golden and the onions have almost completely disintegrated, about 30 min.
6. 6
   Remove from the heat and strain through a sieve into a clean container; discard the contents of the sieve.
7. 7
   Working in batches if necessary, combine the strained stock and the potatoes in a blender or food processor and puree until smooth.
8. 8
   Transfer the puree to a clean saucepan and bring to a gentle boil.
9. 9
   Ladle into warmed soup bowls and garnish each serving with a little of the parsley.