1. Melt butter in a saucepan over low heat.

2. Add onion and celery with leaves; cook until tender.

3. Blend in flour; stir in milk.

4. Cook, stirring constantly, until sauce thickens and comes to a boil.

5. Stir in lemon juice, 1 1/2 teaspoons salt, pepper, marjoram and chicken; remove from heat.

6. Pare potatoes; cut in very thin slices.

7. Place sliced potatoes in a greased 1 1/2-quart baking dish; sprinkle with remaining salt.

8. Pour chicken sauce over potatoes; cover and bake in preheated 425'F. oven 1 hour, or until potatoes are tender.