Autumn Soup Revisited: Potato-Leek Soup

For the home-gardener and cook, making potato-leek soup this time of year is ideal when you don’t know if the temperature is going to be chilly or warm, and rewarding to prepare with ingredients fresh from the garden.

When I first started vegetable gardening it was more for fun than anything else. Along with raising the usual variety of garden plants, herbs and companion flowers, I planted potatoes as a way to connect with my Irish roots.

As it turns out, potato-leek soup is a traditional Irish comfort food, typically served warm during the winter months with buttered, brown soda bread – which makes for a delicious treat on a chilly winter’s day.

But it was my first taste of the velvety chilled version of the soup, known as vichyssoise, with its smooth creamy finish, on a hot summer day that inspired me to grow leeks with this specific dish in mind the following season.

Leeks are easy to grow and frost hardy in our northern climate. The seedlings, started indoors in March and transplanted in April, reach full maturity by autumn, and are harvestable into late fall or early winter, under a thick blanket of mulch.

I learned the technique of “bleaching” the stems, which sweetens them, by starting the seedlings in a trench half-filled with seasoned compost and hilling the soil around the base as the plants grew; keeping the upper stem from which the leaves grow above soil level.

And now, with a bountiful garden harvest in the midst of a typical transitional Vermont autumn of warm days and chilly nights, I’m revisiting the warm version of potato-leek soup called Potage Parmentier, named after the French agronomist who actively promoted the potato for human consumption in France in the late 18^th century.

But hot or cold, I love the comforting potato taste; the subtle sweetness of the leeks and for the way the luscious creamy texture is undercut by the savory flavor of the chicken stock.

And that’s why I love potato-leek soup in autumn: because it’s a versatile and flexible recipe easily adaptable to a variety of substitutions or additional ingredients that can be enjoyed chilled for lunch on a warm day or heated up on a chilly night.

Some hints on technique:

Don’t over-cook the potatoes or the starches will break down and the finished soup will be grainy. For a velvety, smooth finish, make sure that all the ingredients are soft and purée well; then press the soup through a fine-sieve. When re-heating: check for consistency and add cream or stock accordingly. For more color use Yukon Gold potatoes. Note: chilling dulls the flavor, so taste before serving and add salt & pepper as needed.

Creamed Potato-Leek Soup

Serves 4

Ingredients:

2 medium-sized leeks: trimmed, washed & sliced; white and pale green parts only.

3 or 4 medium-sized, firm-fleshed Russet potatoes; peeled and diced

2 tablespoons butter

1 cup heavy cream

1 quart chicken stock

Coarse salt and fresh ground pepper

The basic procedure:

1. In a large stock pot melt butter over low heat. Add leeks, coat in butter and cover, and cook over medium-low heat about 15-20 minutes, or until soft. Stir occasionally, not allowing butter or leeks to brown.
2. Add potatoes and season with salt and pepper. Add chicken stock and bring to a boil, reduce heat and simmer, partially covered until potatoes are soft. Remove from heat.
3. Purée soup with an immersion blender, or food processor in small batches, and let cool.

Slowly whisk in cream. If serving this soup warm, reheat the soup slowly so that the cream does not separate and change consistency. If serving chilled; refrigerate for at least 3 hours.