Meringue Shells a La Heloise

Beat egg whites until stiff and dry; slowly add sugar, then vanilla and vinegar.

Beat again until stiff and dry.

Place meringues on the back of an ungreased cookie sheet, keeping in mind they will double in size.

Make a well in the center of each and bake on the middle shelf of a 250° oven for 1 hour or more until they turn pinkish beige in color.

Test bottom of well with finger; it must not be too sticky.

Bake longer, if necessary. Using a spatula, remove from sheet the minute they come out of the oven.