Spinach & Ginger Soup

We have dinner party tomorrow night:) I made Spinach Ginger Soup from cookbook called 1000 low fat.
This soup is so delicious. Our guest will love it.

Ingredients

2 tbsp vegetable oil
1 onion chopped
3 garlic cloves chopped
2 tsp chopped fresh ginger root
9 oz / 250g spinach leaves
1 small lemongrass stalk, finely chopped
4 cups chicken stock
2 big potatoes chopped
1 tbsp rice vinegar
1 tsp sesame oil
salt pepper
4 tbsp coconut milk (optional)

Preparation Method
Heat the oil in a large pan. Add the onion, garlic, ginger and lemongrass stalk and cook over medium heat  fro 3-4 minutes.
Add the spinach leaves to the pan stirring until the spinach is wilted.Add the stock and potatoes to the pan and bring to a boil.
Lower the heat and cover simmer for  about  30 minutes.
Mix with hand blender until smooth. Add the rice vinegar and , then adjust the seasoning to taste with salt and pepper. Drizzle a few drops of sesame oil and coconut milk  into the soup.