Top | Mastering the Art of French Cooking, Vol. 1
(recipe, Julia Child, Louisette Bertholle, Simone Beck)
Leek and potato soup smells good, tastes good, and is simplicity itself to make. It is also versatile as a soup base; add watercress and you have a watercress soup, or stir in cream and chill it for a vichyssoise. To change the formula a bit, add carrots, string beans, cauliflower, broccoli, or anything else you think would go with it, and vary the proportions as you wish.
Potage au Cresson (Watercress Soup): Follow the preceding recipe, but before puréeing the soup, stir in 1/4 lb. (1 packed cup) watercress leaves and tender stems, and simmer for 5 minutes. Off the heat and just before serving, stir in the cream or butter by spoonfuls. Optional decoration: a small handful of watercress leaves boiled for 30 seconds in water, rinsed in cold water, and drained. Vichyssoise (Cold Leek and Potato Soup): Simmer 3 cups peeled and sliced potatoes and 3 cups sliced leeks, white parts only, in 1 1/2 quarts of white stock, chicken stock, or canned chicken broth. Add salt to taste and purée the soup either in an electric blender or through a food mill and then through a fine sieve. Stir in 1/2 to 1 cup whipping cream, then season to taste with salt and white pepper, oversalting very slightly as salt loses savor in a cold dish. Chill. Serve in chilled soup cups and decorate with 2 to 3 Tbsp. minced chives. Culinate editor's notes: For a heartier flavor, replace half of the water with chicken or vegetable stock. For a thicker soup (the recipe makes a fairly thin soup), halve the total liquid or double the potatoes and leeks, from about 2 Russet potatoes and 2 large leeks to 4 each. An immersion blender works well for the puréeing. And other fresh herbs, such as dill or chervil, make a nice change from parsley.