In a medium bowl, combine flour, egg, 1/2 cup water and salt to form a dough.
Cut into thin strips or small pieces.
Bring a large pot of water to boil. Stir in dough, potatoes and onion. Cook 20 minutes, until potatoes are tender.
Drain.
While pasta and potatoes are cooking, cook bacon in a large skillet over medium heat until crisp. Save drippings.
Return pasta and potato mixture to large pot over medium-low heat, and combine with bacon, a teaspoon of bacon grease, milk, cream and salt and pepper. Adjust bacon grease to taste and milk or cream to cover. Simmer 20 minutes, without boiling.