Preheat oven to 400 degrees F. Place the chopped sweet potatoes on a large baking sheet. Drizzle with olive oil and toss. Season with the cumin, chili powder, salt and black pepper, to taste. Place sheet in the oven and roast for 15 minutes. Using a spatula, toss the sweet potatoes. Roast for an additional 10 minutes or until the sweet potatoes are just tender. Remove from oven and set aside.
Place all salad ingredients into a large salad bowl, saving crispy onions and/or tortilla chips for the garnish on top.
Squeeze fresh lime juice over the salad.
Serve with choice of salad dressing. This salad keeps well for 3 days in the refrigerator
Note-I like to roast or grill the corn for the salad. This salad is very flexible. Feel free to add your favorite Mexican toppings to the mix. Don't use the avocado dressing if you need the salad to be vegan.