In a medium bowl, whisk together flour and pecans. In another bowl, using a fork, mash butter, egg yolk, sugar and salt until blended; add to flour mixture. Gradually, mash egg mixture into flour mixture with fork to make a dough that holds together. Press into disc, wrap and refrigerate for 1 hour or until chilled.
Preheat oven to 375°F (190°C) with rack positioned in bottom third. Set out a 9-inch (23 cm) tart pan with removable bottom on a rimmed baking sheet.
Between waxed paper, roll out pastry into an 11 inch (28 cm) circle. Peel off top paper, invert pastry and fit into pan. Trim, if necessary, to leave 1-inch (2.5 cm) overhang; fold inside and press pastry together.
Spread fruit over pastry. In a bowl, gradually whisk cream into flour; whisk in eggs, sugar, lemon rind, vanilla and salt. Pour over fruit.
Bake on baking sheet in bottom third of oven for about 35 minutes or until golden and tip of knife inserted into custard comes out clean. Let cool on rack. (Make-ahead: Set aside at room temperature for up to 1 hour.) Dust with icing sugar and serve with dollop of whip cream (if desired).