1/4 pound (120g) unsalted butter, cut into pieces
1/4 cup (30g) curry powder
4 large onions, cut into chunks
4 cups (1 L) Basic Chicken Stock (page 345) or commercial chicken broth
3 tablespoons fresh lime juice
1 tablespoon kosher salt, or less if using commercial broth
1 cup (250ml) heavy cream, optional
In a mediaum saucepan, melt the butter over medium-low heat. Stir in
the curry powder and cook, stirring, for 2 minutes. Stir in the onions
and cook, stirring occasionally, for 10 minutes.
Pour in the stock. Bring to a boil. Lower the heat and simmer for 10 minutes, or until the onions are very soft.
In a blender, working in batches of no more than 2 cups (500ml),
purée the soup until very smooth, stopping once or twice to
scrape down the sides of the jar. Scrape the purée back into the pan. The soup can be made ahead up to this point and refrigerated.
Heat the soup through. Remove from the heat and whisk in the lime juice, salt and, if using, the heavy cream.
Makes 7 cups (1.75L) without cream, 8 cups (2L) with; 6 to 8 first-course servings