Baked sweet potato salad

2 1/2 pounds sweet potatoes
1 red bell pepper
3 stalks celery, (about 1 cup chopped)
1/4 red onion, thinly sliced
Cilantro Lime Yogurt Dressing:
1 cup nonfat yogurt
1 tablespoon minced fresh cilantro
1 tablespoon minced scallions
2 teaspoons fresh lime juice
Salt, to taste

1. Preheat oven to 400 F. Wash the sweet potatoes, pierce them with a fork several times, and bake until soft, 40 to 60 minutes. Meanwhile, prepare the dressing and store in the refrigerator.
2. While the dressing chills, seed and chop the red onion, chop the celery, thinly slice the 1/4 red onion. Place all the prepared ingredients in a large bowl and set aside.
3. Remove the baked sweet potatoes from the oven, and when they are cool enough to handle, peel and cube them. Add them to the bowl and gently toss with the other ingredients. Carefully stir in the dressing. Serve warm, room temperature, or chilled
4. Cilantro Lime Yogurt Dressing: In a small bowl, combine the yogurt, cilantro, scallions, and lime juice. Add salt to taste. Set aside for at least an hour to allow flavors to meld. Will keep 3 to 4 days in refrigerator.