Bring enough water to cover the beets to a boil in medium saucepan. Put the beets in the boiling water and cook for about 20-25 minutes, until the beets are still firm but easily pierced by a fork. Drain the beets in a collander and place under cold running water until they are cool.

Bring enough water to cover the potatoes to a boil in medium saucepan. Put the potatoes in the boiling water and cook for about 15 minutes, until the potatoes are still firm but easily pierced by a fork. Drain the potatoes in a collander and place under cold running water until they are cool.

Meanwhile, in a large mixing bowl whisk together the canola oil, vinegar, mustard, chopped parsley, and salt and pepper. Blend in the red onion, celery, and apples. Then toss the cooled beets and potatoes in with the vinaigrette mixture. Chill for one hour before serving.