1. Cut potatoes into 1/2 inch slices and place in a steamer. Steam potatoes for 8 minutes, or just until tender.
2. Toss steamed potatoes with 2 tablespoons lemon juice and let cool. Drain lemon juice from potatoes.
3. Add olives, celery, red pimento, onion and feta cheese. Toss gently.
4. DRESSING: Combine 3 tablespoons lemon juice, oregano, salt, and olive oil. Pour over salad and gently toss. Refrigerate overnight to blend flavors.