Remove the fibres from the celery and cut into thin sticks (slightly longer than the diameter of the bread). Halve the walnut kernels. Cut cheese into sticks. Peel and quarter pear, remove core. Cut quarters into thin slices
Grill slices of bread in a greased grill pan. Place on a baking tray lined with baking paper. Spread the pear, celery and cheese sticks on top
Bake the crostini under the hot grill for 2-3 minutes. Garnish with a leaf of coriander, sprinkle with pepper and serve