Coconut Milk Salmon Soup

3 3/4 cups light chicken or vegetable stock
1 stalk fresh lemon grass, chopped
1/2-inch piece fresh ginger root, peeled and chopped
Grated zest of 1 lemon
1/2 dried red chili
6 ounces salmon fillet, skinned
1 tablespoon cornstarch
1 tablespoon lemon juice
1 x 12-ounce can coconut milk
salt and pepper
Small bunch cilantro, chopped

Put the stock in a pan with the lemongrass, ginger, lemon zest and chili. Bring to a boil, then simmer for 10 minutes. Strain. Puree the salmon in a blender or food processor. Pour a cupful of the stock through the feed tube, then add the mixture to the rinsed-out pan along with the rest of the stock. Mix the cornstarch and lemon juice together and add them to the pan along with the coconut milk. Season to taste. Cook, stirring over medium heat until the soup thickens. Sprinkle with the cilantro and serve.
SERVES 4