Preheat the grill to hot.
Spread 4 of the slices of bread with the cheese (keep it in a warm place for a while before hand to soften it). Top with slices of red onion, pear and also the finely chopped walnuts and the chopped chives. Place the other slices of bread on top to make sandwiches.
Grill for 2-3 minutes on both sides under the grill until golden brown and toasted. Serve on napkins, topped with slices of red onion and rocket leaves on the side.