Preheat the oven to 375°F (190°C).
Take the tart pan with the pâte sucrée from the refrigerator. Prick the bottom with a fork and line it with a few opened and fanned-out coffee filters or a piece of parchment paper. Fill the lined tart shell with beans or pie weights and bake 15 minutes, until set. Take the tart out of the oven and carefully lift out the paper and beans. Return the tart to the oven and bake another 10 to 15 minutes, until the crust is an even golden brown. Set aside on a rack to cool completely.
Melt the chocolate in a double boiler over medium-low heat. Spread the chocolate evenly on the crust and chill in the refrigerator for at least 15 minutes, until the chocolate has solidified completely.
While the crust is chilling, make the curd. Whisk the eggs, yolks, sugar, and lemon juice together in a heavy-bottomed saucepan. Cook over medium heat, stirring continuously, alternating between a whisk and rubber spatula (see note above), until the lemon curd has thickened to the consistency of pastry cream and coats the back of the spatula.
Remove the lemon curd from the heat. Add the butter a little at a time, stirring to incorporate completely. Season with the salt. Let the curd cool about 8 minutes, and then strain it into the prepared tart shell. Chill the tart in the refrigerator.
Just before serving, whip the cream in a stand mixer fitted with the whisk attachment (or by hand) until it holds soft peaks. Cut the tart into six wedges, plate them, and serve with dollops of whipped cream. Originally published April 15, 2005.