tarte aux oignons d'alsacerating:
Trad. Jewish recipe, courtesy Claudia Roden.
Rub together, or throw in blender
250g plain flour
and add an egg, and enough milk (1-2 tablespoons) to turn into pastry. Roll into a ball, wrap in plastic and refrigerate for an hour. Meanwhile, slice and fry
3/4 kg onions
in some butter and oil for an hour. A very low heat and occasional stirring will help here; we want them golden and sticky rather than burnt. Add two tablespoons of plain flour, stir and take off heat. Beat together
250 mL double cream
and add to the (cooled!) onion mix and stir throroughly. Get pastry out of fridge and press with your hands into a 10 inch pie dish. Pour in filling and bake for a hour in pre heated oven at 150 degrees celsius (gas mark 2).
I think that's 0.75kg onions rather than three or four.