In abowl combine the olive oil, cumin, sugar, black pepper, ans salt. Lay the salmon on a foil lined baking sheet and brush the top with the oil mixture. Refridgerate for 10-20 minutes.
Preheat the broiler. Combine the yogurt, cucumber, scallion, parsley, lemon juice and the remaining pinch of salt in a small bowl.
Broil the salmon 7 to 10 minutes. Serve over the orzo, topped with the yogurt sauce.