Step #1 --FILLING----- 400F g Onions 30 g Bacon, salt & a little of the water, beat the egg and add it, cut into thin strips 50 g Unsalted butter 3 1/2 dl Cream 3 1/2 dl Milk 4 Eggs 1 ds Gratted nutmeg 1 tb sliced parsley Salt & pepper Pastry Make the flour into a 'well' on the pastry board, with the butter, then work the ingredients into the flour with your fingertips, to the centre of the well, incorporating more water little by little; whether you have to use all the water or not depends on the quality of the flour.
Step #2 Press all the dough together into a ball then, finally, work it thoroughly with the heel of your hand, gathering it up with pastry scraper as you do so until it is soft & pliable.
Step #3 Leave it in the refrigerator to firm up again before you roll it out.
Step #4 Filling Peel the onions.
Step #5 Cut them into fine rings & weigh out 300F g.
Step #6 Cook the bacon strips (which need to be VERY finely cut) in the butter.
Step #7 Let them take on a golden colour, then add the sliced onions & leave them to cook carefully until they are tender.
Step #8 In a bowl beat together the cream, adding salt, milk & eggs, pepper & nutmeg to taste.
Step #9 When the onions are cooked, add them to the mixture in the bowl and add the sliced parsley.
Step #10 Preparation Roll out the dough 2mm thick & use it to line a buttered tart tin 26 cm in diameter & at least 3cm deep.
Step #11 Cut a disc of aluminium foil of the same diameter as the tin & place it on the pastry.
Step #12 Weight it down with a handful of beans or crusts.
Step #13 Pre-heat the oven to 150 oC (300 oF) & cook the pastry 'blind' for half an hr.
Step #14 Watch the coulouring of the edge & as soon as it starts to turn golden remove the aluminium foil & beans or crusts.
Step #15 Cook the pastry shell until the base is baked but not coloured.
Step #16 Fill the shell with the onion mixture.
Step #17 Put the tart back into the oven.
Step #18 Check that the temperature is still 150 oC & keep the oven at or just below this temperature for about 1 hr.
Step #19 Towards the end you could reduce the heat a little, as the tart needs TO COOK VERY SLOWLY.
Step #20 The tart is ready if, when you shake it, the filling appears to be quite firm with no hint of a whole in the centre.