1 In a medium bowl, stir together dates, bacon, chutney, walnuts and rosemary. Finely chop or grind remaining 1/4 cup walnuts and place in a small dish.
2 Place pastry on a board. Mound date mixture in center and spread level to 4” circle. Place Brie on top. Brush exposed pastry with water.
3 Gather and pleat pastry to cover Brie. Snip off excess dough with kitchen shears. Press with hands to flatten and seal seams. Invert onto parchment-lined baking sheet.
4 Preheat oven to 400ºF. Bake for 20 minutes; brush with egg and bake 5 minutes more or until golden brown. Set aside to cool slightly, about 30 minutes. Transfer to a platter and garnish with rosemary sprigs. Use a serrated knife to cut into wedges.
MAKE AHEAD: Recipe can be assembled and refrigerated, wrapped airtight, one day in advance up to and including Step 3. Or, double the recipe and freeze one for another occasion.
TIP: Cut out decorative leaves with pastry scraps to decorate top of pastry.