Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1 1/2  cups          plain yogurt
     3/4  cup           mayonnaise
   1 1/2  tablespoons   white wine vinegar -- or to taste
     3/4  cup           minced fresh parsley
   1      large         red onion -- quartered and
                        -- sliced
     3/4  cup           finely chopped fresh herbs -- basil, dill, etc.
   1 1/2  pounds        tricolor pasta

Preparation:

In a large bowl whisk together yogurt, mayonnaise, vinegar, parsley, onion and herbs. Cook pasta until tender, about 12 minutes. Drain pasta and rinse with cold water. Drain and toss with dressing and salt and pepper to taste. Salad may be made 4 hours ahead and chilled, covered. If pasta absorbs dressing while standing, toss with about 3 tbsp warm water.