Preheat oven to 350' F and lightly butter a 9" heavy pie plate. (I use a Pyrex glass pie plate)
In blender add eggs, milk, sugar, vanilla, nutmeg and salt and blend well for 30-60 seconds.
Add flour and blend again until smooth, 60 seconds, then pour into greased pie plate.
Arrange the sliced plums over the top and bake in oven 25-30 min. Clafoutis will be lightly browned and should still have a slight jiggle in the middle.
Let cool slightly and serve warm, sprinkled with confectioners sugar.If serving later, rewarm slightly before serving.
Notes
The proper consistency is like a clafoutis which is in between a cake and a custard. It is best achieved by not over cooking.