Tuna with Tomatoes and Olives

In a large frying pan over high heat, warm 2 tablespoons of the olive oil. Season the tuna with salt and pepper. Add to the pan and sear over high heat, turning once, just until golden brown, about 3 minutes. Transfer to a plate and set aside. Add the remaining 2 tablespoons oil to the pan and reduce the heat to medium-high. Add the onion and saute until softened, 3 - 4 minutes. Add the garlic and saute for 30 seconds. Stir in the tomatoes, wine, red pepper flakes, olives, and capers. Cover the pan and simmer to blend the flavours, for about 5 minutes. Uncover and stir in the pine nuts. Return the tuna to the pan, spooning the sauce over it,until it is opaque throughout and the sauce is slightly reduced, 7 - 10 minutes. Transfer the tuna steaks and sauce to warmed plates and sprinkle with the basil. Serve at once. Serve with Spicy Couscous.