Pre-heat oven to 200C. Combine eggs and half the sugar in a medium bowl and whisk lightly. Add milk and vanilla and whisk to combine. Cut bread in half (into triangles) and place a square of chocolate on each slice. Layer bread, overlapping slightly, in a lightly buttered, medium ovenproof dish (about six-cup capacity). Pour egg mixture over bread and bake for 35-45 minutes or until top is golden and custard is set.

Meanwhile, combine blueberries and remaining sugar in a pan. Stir over medium heat until juices begin to run, then cook for one to two minutes until syrupy. Berries should still hold their shape. Serve warm pudding with blueberry sauce drizzled over.