Preheat oven to 400 degrees F. Over medium heat, bring water, butter, and salt to boil, in a large sauce pan. Add flour all at once and stir into a smooth ball. Remove from heat and allow to cool for 5 minutes. Add eggs one at a time, and beat after each egg. Continue to beat until smooth and shiny. Prepare cookie sheet with a non-stick coating. Drop mixture by 1/4 measurements onto cookie sheet. Combine milk and egg yolk and brush over each puff. Place in oven for 35 to 40 minutes or until golden brown.
Upon removal of oven, cut slit in each puff to allow steam to escape and place on wire rack to cool.
Finely chop a handful of strawberries in small bowl. In separate large bowl, beat cream until it begins to thicken. Add sugar, vanilla and chopped strawberries and beat until almost stiff. Split puffs, discard soft centers, and fill with cream. Garnish with strawberries and dust with additional confectioners' sugar. This recipe makes about 10 cream puffs.