chilled watercress and spinach soup

Serves: 4

Ingredients:
2 tablespoons olive oil
1 small onion (peeled and chopped)
1 small potato (peeled and diced)
3 cups watercress (washed and thicker stalks removed)
1 cup spinach
2½ cups low sodium vegetable stock
salt and black pepper
½ teaspoon lemon juice

Method:
in a pan, heat the olive oil and add the onion and potato. sauté for 5-7 minutes until the vegetables are soft but not brown.
add the watercress and spinach, season well. cover with the stock and cook for 4 minutes or until the leaves have wilted.
remove and cool. add in the lemon juice and puree the soup. cover and refrigerate overnight.
serve chilled.