2 egg whites
 1/2 cup seasoned rice vinegar
 1/2 cup peach preserves
 1 T garlic, minced
 1 T whole grain or dijon mustard
 1/4 cup sour cream, non-fat works OK
 juice of one lemon
 Place the above ingredients in a blender or food processor and blend.  
 While blending, add olive oil in a steady stream, a little at a time, 
 until dressing is thickened.  
 Season with salt and pepper.