This recipe uses two cups of salad; you can vary the measurements of the ingredients according to how much leftover salad you have. I think broth is essential here, or at least the water from steamed vegetables.
2 c leftover dressed salad
1 T vegetable oil
2 c broth
2 c buttermilk or yogurt
salt and pepper
chives, scallions or fresh herb, chopped, for garnish
1. Saute salad briefly in oil in a large pot. Add broth and cook for 5 minutes. Remove from heat and allow to cool for about 10 minutes. Place broth mixture in a food processor or blender and puree until smooth.
2. Pour into a serving bowl or back into the pot, (if you’re serving en famille), add buttermilk or yogurt and seasonings and blend well.
3. Chill for at least an hour. Serve with garnish.