Alturas Casserole

3 potatoes, cut in half crosswise
1 lb. fillet of sole
1 tbsp. lemon juice
1 tsp. salt
1 medium onion, sliced
1 medium red pepper, sliced
1 medium green pepper, sliced
½ tsp. white pepper
1 large tomato, sliced
2 tsp. butter

Cook potatoes in 1 inch boiling salted water in covered saucepan for 20 to 25 minutes or until tender but not crumbly. Drain and peel; cut into 1/8 inch slices.

Arrange sole in single layer in shallow baking dish. Sprinkle with lemon juice and ½ tsp. salt. Let stand for 30 minutes.

Place layer of potatoes in shallow 2 quart casserole. Layer half the onion and red and green pepper slices over potatoes. Arrange sole in single layer over vegetables; sprinkle with salt and pepper. Layer onion, pepper slices, tomato and potatoes in order listed over sole. Dot with butter.