German Style Buttermilk Potato Salad

I use buttermilk often in my cooking.  It is very low in fat, so I use it to make salad dressings, for baking, in cream soups, and to make the creamiest mashed potatoes without using lots of butter.
My husband is a big meat and tater kind of guy.
Since it was Father's Day yesterday, we had a cookout:  burgers, a pasta salad with lots of vegetables, and this German style potato salad.  Although we love the mustard kind of potato salad, this is a new family favorite.  It's made with new red potatoes with the skins still on, and the dressing is loaded with chives and dill.  Very fresh, and different from the same old.
Of course, when I went to the store, I forgot the fresh buttermilk.  I keep buttermilk powder on hand, so I substituted regular milk and added 2 tsp of buttermilk powder to the dressing.  It doesn't mix in easily, so I blended it with the milk before adding it to the dressing.  

German Style Buttermilk Potato Salad
2 lb baby red potatoes
1/3 C low fat Miracle Whip
1/3 C red wine vinegar
1 1/2 C buttermilk
2 tsp lemon juice
3 heaping T chopped chives
1/4 C finely chopped dill
1 tsp garlic powder
salt and pepper to taste
In a large pot, cover the washed potatoes with cold water and put them on to boil.  In a quart jar with a lid, add the dressing ingredients, and shake until well combined.  When the potatoes test done by slipping easily from a knife, drain and slightly mash with a potato masher to break the baby potatoes up in smaller pieces.  Dress with the whole jar of dressing and cover the bowl with foil, or a dinner plate to keep the salad warm until serving time.  It was even better for lunch today!