Cook potatoes in boiling water for 20 minutes. Cook green beans in salted water until tender but still crunchy. When potatoes are cool enough to handle, peel, and cut into 4 pieces. Combine with green beans in a salad bowl. Melt butter in medium sized skillet. Add bacon and saute until crisp about 4 minutes. Pour bacon and skillet drippings over potates. Deglase skillet with vinegar and reduce vinegar by 2/3 about 1 minute. Pour over vegetable and combine well. Season with salt and pepper. Sprinkle with shallots and parsley.