2 sweet potato, peeled and cut into 3/4-inch cubes
2 potatoes, peeled and cut into 3/4 inch cubes
2 teaspoons distilled white vinegar
1/4 cup light mayonnaise
1/4 cup light sour cream
2 teaspoons fresh lemon juice
1 teaspoon curry powder, or to taste
salt and ground black pepper to taste
1/4 cup chopped green onions
1/2 cup chopped celery
1 tablespoon chopped fresh cilantro