Michel Richard of Citrus likes to use brioche in this homey pudding, but white bread also works well.
Heat oven to 325 degrees. Line a 10-by-2-inch round ovenproof glass dish with plastic wrap. Thinly slice pear quarters lengthwise, but don't separate slices. Arrange in an attractive pattern on pan bottom. Place bread slices in two overlapping layers on top.
In a medium bowl, whisk together milk, cream, eggs, brown sugar, coriander, and salt. Pour over bread slices.?
Place baking dish in a pan filled with enough boiling water to reach halfway up sides of dish. Cover pan with foil; bake for 1 hour.
Cool completely and unmold pudding onto a serving plate. Discard plastic wrap. Refrigerate pudding until ready to serve.
To make Caramel Sauce, heat sugar and lemon juice in a heavy, medium saucepan over low heat until mixture turns deep amber. Carefully stir in milk and pear-poaching liquid; boil for 1 minute, until smooth. Strain and use immediately.
To serve pudding, cut into slices, inserting Bartlett pear slices between each pudding slice. Serve with Caramel Sauce.