2 tbsp. vegetable oil
1 c. chopped onions
2 lbs. carrots, chopped (5 c.)
1 c. chopped celery
2 tsp. minced garlic
2 cans (14 1/2 oz. each) chicken broth
4 c. water
1 c. peeled, diced all-purpose potato
3/4 tsp. salt
1/4 tsp. freshly ground pepper
1/4 tsp. thyme
Chervil sprigs, for garnish
1/2 c. plain non-fat yogurt

Heat oil in large saucepot over medium heat. Add onions and cook until translucent, 3 minutes. Stir in carrots and celery; cook 10 minutes more. Stir in garlic and cook 30 seconds. Add chicken broth, water, potato, salt, pepper and thyme. Bring to a boil, reduce heat and simmer uncovered 30 minutes. Cool slightly. Puree in blender in batches.

Can be made ahead. Cool completely. Cover and refrigerate up to 24 hours. Reheat covered in saucepot, stirring occasionally, until hot-- 20 minutes. This is also good cold. Add an extra spoonful of yogurt if you like it more tangy.