Place potatoes in a saucepan and cover with water. Bring to a boil. Reduce heat; cover and cook for 15-20 minutes or until tender. Drain and cool.
Cut potatoes into quarters; place in a large bowl. Add the celery, red pepper, hard-boiled eggs and onions. In a small bowl, combine the remaining ingredients. Pour over potato mixture and toss to coat. Cover and refrigerate for at least 1 hour.