When Barbara Lauterbachs daughter Lisa had her first child, Barbara loaded her car with enough food to sustain the new family over that first anxious week. This salad,from Barbara's book Potato Salad, was among the offerings; the sweet potatoes and butternut squash provided nutrition for the new mother, while the tangy dressing and tart cranberries were refreshing.

1. Preheat the oven to 400°F. Scrub the sweet potatoes with a stiff brush but do not peel. Prick in several places with the tines of a fork. Bake until just tender when pierced with a fork, about 30 minutes. Alternatively, scrub and prick the potatoes and microwave on high for 6 to 8 minutes. Don't overcook or they won't cut nicely. Let cool completely and cut into 1/4-inch cubes.

2. In a large pot filled with water, boil the Yukon Gold potatoes for 20 to 25 minutes, or until just tender. Drain well. When cool, peel and cut into 1/4-inch cubes.

3. Cook the butternut squash cubes in boiling water to cover until just tender, about 5 minutes. Drain well.

4. While the potatoes are cooking, make the dressing: In a bowl, mix together the sugar, dry mustard, and salt. Stir in the onion and 2 tablespoons of the cider vinegar and mix until smooth. Gradually beat in the oil and the remaining vinegar. Add the celery seed. Blend well.

5. To assemble the salad, in a large bowl, gently mix together the Yukon Gold potatoes, sweet potatoes, squash, and parsley. Add the dried cranberries, red onion, and walnuts, then pour the dressing over all. Mix gently. Cover and refrigerate, then bring to room temperature before serving.

To make ahead: The dressing can be made up to 2 days ahead, covered, and refrigerated. Once dressed the salad will last, covered in the refrigerator, for up to 2 days.