Place all of the ingredients for the crust, except the vinegar, into the work bowl of a food processor equipped with the steel blade, and pulse 3 or 4 times, until the mixture has the consistency of coarse meal. Slowly, with the machine running, add the v
Prick the bottom and sides of the chilled dough all over with a fork or docker. Line the pan with foil or waxed paper, fill with pie weights, rice or dried beans (or use another, perforated pie pan), and bake for 12 minutes. Remove the crust from the oven
Place all of the filling ingredients into the work bowl of a food processor (or into a blender), and process until smooth and creamy.
Spoon the filling into the baked crust. Slice the cucumberand radishes (using the food processor's 1mm blade, if possible), and alternate the slices around the edge of the tart. Place the egg whites on the center of the tart, then the yolks on top. Decora