Honey Walnut Filling
For pastry, cream butter and icing sugar until smooth. Stir in egg yolks. Blend in flour and salt until dough comes together. Shape into a disk, wrap and chill for at least 2 hours.
Preheat oven to 350 ?F (180 ?C). Divide dough into 6 pieces and, on a lightly floured surface, roll out each piece to ¼-inch (4 mm) thickness and line 6 4-inch removable-bottom tart shells. Trim edges of shells and place on a baking tray. Prick bottom of shells with a fork and bake for 18 to 20 minutes, until edges of pastry just begin to brown. Cool before filling.
For filling, reduce oven temperature to 275 °F. Melt butter in a bowl over a pot of gently simmering water. Stir in sugar, eggs, honey, vanilla, salt and cinnamon. Whisk mixture until shiny and thickened, about 7 minutes. Remove from heat and stir in walnut halves. Sprinkle chocolate chunks over cooled crusts and spoon walnut filling into each shell. Bake for 35 to 45 minutes, until tarts are set. Cool for at least 15 minutes before unmoulding. Serve warm or at room temperature.
Great with a scoop of maple walnut ice cream!