In a spice grinder, coarsely grind peppercorns. Coat the tuna with the peppercorns, pressing them into the flesh of the fish. Add oil to a hot saute pan. Sear the tuna in the saute pan, for about 1 minute per side. Remove tuna from the pan and slice into 1/4 inch thick slices. In a saucepan, combine the soy sauce and orange juice and bring to a boil. Boil the soy sauce mixture until reduced by 70 percent and has achieved a syrup consistency. Cool. Whip the cream. Fold in the wasabi powder. Drizzle a little orange soy sauce onto each slice of tuna. Top with a little wasabi cream.