Chef Darina Allen of Ballymaloe Cooking School - County Cork, Ireland
Adapted by StarChefs

Watercress is frequently mentioned as a foodstuff in the twelfth-century manuscript Agallamh na Seanorach (The Colloquy of the Old Men). Legend has sit that it was watercress that enabled St Brendan to live the ripe old age of 180! In Birr Castle in Co. Offaly, Lord and Lady Rosse still serve a soup of watercress gathered from around St. Brendan's well, just below the castle walls.

Yield: 6 Servings

  • 3 Tablespoons sweet (unsalted) butter
  • 1 1/4 cups potatoes, peeled and chopped
  • 1 1/4 cups yellow onion, chopped finely
  • Kosher salt and freshly ground pepper, to taste
  • 2 1/2 cups chicken stock or vegetable stock
  • 2 1/2 cups creamy milk
  • 2 bunches of chopped watercress (remove the coarse stalks)


Melt the butter in a heavy-bottomed sauté pan. When it foams, add the potatoes and onions and toss until well coated. Sprinkle with salt and freshly ground pepper. Cover the pan and sweat the vegetables over low heat for 10 minutes. Add the stock and milk, bring to a boil and cook until the potatoes and onions are soft.

Add the watercress and boil with the lid off for approximately 4 to 5 minutes until the watercress is cooked. It will taste soft and tender. Do not overcook or the soup will loose its fresh green color.

Puree the soup in a blender or food processor. Taste and add a little more salt and pepper if necessary. Divide among 6 soup bowls and serve.