Heat 1 inch salted water (1/2 teaspoon salt to 1 cup water) to boiling; add potatoes.
Heat to boiling; reduce heat and cover and cook until tender.
Drain and cool slightly.
Cook onion in oil until tender; mix onion, oil, sour cream, salt and pepper.
Peel potatoes and cut into 1/4 inch slices; gently mix potatoes and sour cream mixture.
Arrange half the potatoes in greased 10x6x1 1/2 inch baking dish or 1 1/2 quart casserole; arrange eggs on top and add remaining potatoes.
Sprinkle with bread crumbs and paprika; bake, uncovered, at 325 degrees until light brown, 30 to 40 minutes, then garnish with snipped parsley if desired.