Press the just-made pastry over the base and up the sides of a buttered 24 cm (9½ inch) fluted loose-bottomed tart tin using fingers dusted in rice flour until the pastry stands a little above the top of the tin. Trim with scissors to neaten. Prick the base with a fork, put on a baking sheet and chill for 15 minutes.
Bake the tart blind (see
Cream the butter and sugar together until light and fluffy. Add the ground almonds, eggs and almond essence and beat until smooth. Fold in half the chocolate.
Toss the pears in the lemon juice and arrange half in a random pattern in the base of the tart. Spoon the almond frangipane over the top and spread as evenly as you can. Press the remaining pears into the filling, then sprinkle with the flaked almonds. Bake for 30–40 minutes until the frangipane is golden and just set. Check after 20 minutes and cover the top loosely with foil if the almonds seem to be browning too quickly. Leave to cool for 30 minutes.
Remove the tart from the tin, sprinkle with the remaining chocolate and dust with icing sugar. Serve warm or cold.