Set the tuna steaks in a glass or porcelain dish. Blend 2 tab. olive oil, rice wine vinegar, soy sauce, ginger and dried pepper flakes. Add tuna steaks and marinate for as long as possible.
Meanwhile in a glass bowl combine the orange and lemon juice, cumin, 2 tab olive oil and orange supremes.
Broil or grill tuna for 3 minutes a side; you want the tuna rare. Cut it into thin strips and set over couscous; garnish with oranges and fresh mint.