By Martha Rose Shulman
YIELD 16 to 18 demitasse servings or 8 bowls TIME About 1 hour 30 minutes
INGREDIENTS
1 tablespoon extra virgin olive oil
1 medium onion, chopped
2 leeks, white and light green part only, halved lengthwise, cleaned and sliced or chopped
Salt to taste
2 pounds celeriac, peeled and diced (retain tops for bouquet garni and garnish)
1 large russet potato (about 3/4 pound), peeled and diced
2 granny smith or braeburn apples, cored, peeled and diced
2 quarts water, chicken stock, or vegetable stock
A bouquet garni made with a bay leaf and a couple of sprigs each thyme and parsley, and a stem or two of the celery from the celery root, if still attached
Freshly ground pepper to taste
GARNISH
Slivered celery leaves for garnish
Step 1
Heat the olive oil in a large, heavy soup pot over medium heat and add the onion, leeks and a pinch of salt. Cook, stirring, until tender, about 5 minutes. Add the celeriac and a generous pinch of salt, cover partially and cook for another 5 minutes, stirring often, until the celeriac has begun to soften. Add the potatoes, apples, water or stock, salt to taste, and the bouquet garnish. Bring to a boil, reduce the heat, cover and simmer 1 hour, or until the vegetables are very tender and the soup is fragrant. Remove and discard the bouquet garni.
Step 2
Blend the soup in batches in a blender (cover the top with a towel and hold it down to avoid hot splashes), or through a food mill fitted with the fine blade. The soup should be very smooth. Strain if desired. Return to the pot. Stir and taste. Adjust salt, add freshly ground pepper, and heat through. Serve in small bowls or espresso cups, garnished with thin slivers of celery leaves.