Sweet Potato Salad with Edamame and Walnut Dressing

This is a fast, fresh potato salad with crunchy pickled red onions, which contrast the softness and sweetness of the potatoes.  This is a great side dish, or a main dish for a lunch or light dinner.
1 large sweet potato, diced 1/2-inch, about 2 cups
1/2 large red onion, sliced, about 1 cup
1 cup shelled edamame
1 yellow pepper, diced

Marinade for onions:
1/4 cup red wine vinegar
Juice of 1 lime

To complete dressing:
1 tsp mustard
1/4 cup walnut oil
Extra virgin olive oil as needed

Mix marinade ingredients in a shallow dish.  Slice onion and marinate the for 1/2 hr in the shallow dish.  Stir often.

Meanwhile, cover sweet potatoes in a medium pot with cold water.  Bring to a gentle boil and cook just until tender to the tip of a knife.  Add the edamame for the last minute or two of cooking.  Drain potatoes and edamame. 

Drain onion and add to potatoes.  Whisk together the remaining dressing ingredients with the marinade.  Fold into the potato mixture and tip into a serving bowl.  Let salad rest for 20-30 minutes to let the flavors penetrate the potatoes.

Serves four as a side dish.

Cook's note:  Topping this salad with toasted walnuts and/or crumbled gorgonzola cheese are great options for this salad.