With this particular tart, as it has a moist filling, it's important to egg-wash the uncooked tart shell before adding the filling. This adds a sort of waterproof layer and keeps the pastry crisp and short for longer.
Whisk together the sugar and eggs in a bowl. When they are well mixed, slowly stir in the cream and the juices. Put the cooked tart shell back into the oven and then pour the filling into it -- I find this reduces spillage. Bake for around 40 to 45 minutes at 180C/350F/Gas 4 or until the filling is set, but still semi-wobbly in the middle (obviously different ovens will cook at different rate so it is good for you to try this tart a couple of times to gauge exactly when you should take it out of the oven). After cooling for an hour, the semi-wobbly filling will have firmed up to the perfect consistency; soft and smooth. If you cut it before it has had time to rest it will pour out or be extremely gooey.
You can dust it with a little icing sugar, if you wish. Serve with a huge pile of fresh raspberries or strawberries. Whatever you decide to serve it with should be quite simple so that you let the tart do the talking.