Welsh Leeks & Potatoes

2 pounds potatoes, pared and sliced thin
1 ½ cups chopped leek (or more)
4 Tbsp margarine
1 tsp salt
Freshly ground black pepper
Pimiento, optional

Preheat oven to 350°F. Layer about one-third of the potato slices into a well-greased 9x1½-inch pie plate and sprinkle with half the leek. Dot with butter and season lightly. Repeat, ending with a layer of potatoes, butter, and seasonings. Cover with foil and bake 1 hour. Remove foil, test for doneness. Bake up to 30 minutes longer or until lightly browned and tender. Yield: 6 servings.