You will need:
4 cups of fresh watercress.
1 cup buttermilk
4 cups chicken or vegetable broth
1 boiled, lightly mashed russet potato to equal about 2 cups
2 cloves of garlic finely chopped
2 tablespoons garlic infused olive oil
salt, pepper and truffle oil.
In a pan add the olive oil, onions and garlic, sautee until translucent. Add the broth, potato and watercress, salt and pepper and bring to a boil for about one minute. Reduce heat and let simmer. After the heat has gone down, slowly add the buttermilk and simmer about 5 to 7 minutes. Then puree in a blender until smooth. I usually add it back to the pot to stay warm while I poach the egg, set the table, etc.