Chilled Czech Blueberry Soup (Boruvkova polevka studena)

3 cups blueberries
4 cups water
Pinch of salt
1 tablespoon granulated sugar
1 1/2 cups sour cream
6 tablespoons flour
1/4 teaspoon cinnamon

Boil 2 cups of the blueberries in the water. Stir in salt, cinnamon and sugar. Remove from heat.

Whip flour into the sour cream, then whip both into the hot liquid. When well blended, return the pot to the heat and bring to a boil. Reduce heat and stir until thickened.

Remove from heat, stir in another 1/2 cup of blueberries, and chill in refrigerator.

When ready to serve, stir in the remaining 1/2 cup of blueberries and ladle into bowls.