This was an old standby in our house when I was growing up in Pennsylvania Dutch Country. My mother would always make this for out-of-state visitors. It's a perfect example of the "sweet/sour" recipes that the PA Dutch are known for. This dressing can be used on iceberg lettuce or as a dressing to make German style potato salad as pictured.
In a large serving bowl, tear lettuce into bite size pieces. Set aside.
Cook the bacon in a 10-inch non-stick skillet. Remove bacon from skillet when cooked and set aside. Do not discard bacon fat. You will be using it to complete the cooked dressing.
In a medium bowl, combine the egg, sugar, flour, water, vinegar, salt and pepper. Mix well and add to skillet with bacon fat. Cook, stirring constantly, for about 4-5 minutes or until dressing thickens and is hot and bubbly. Crumble bacon and add to skillet. Mix well.
Pour hot dressing over lettuce and toss to coat.
Please note: this dressing can be used to make German Potato Salad as well. Just substitute 3 pounds of cooked, diced potatoes for the lettuce. Add 1 stalk of celery, diced and 1 small onion, diced and you have another PA Dutch style salad!!