Hard-boil the egg, then peel and slice it.
Wash the beets but leave the 'tail' attached.
Boil rapidly for 45 minutes, until tender, then peel and chop into small cubes.
Chop the celery.
Combine the vegetables in a wooden bowl, then mix the oil, vinegar, salt and pepper and pour the dressing over the salad.
Toss gently and serve on a bed of lettuce, topped with slices of hard-boiled egg and chopped chives.