How to Make It
Preheat the oven to 200°. Rub the tuna steaks on both sides with the canola oil and sprinkle them with the salt and pepper. Arrange the steaks on a serving plate, or on 4 dinner plates and bake for about 20 minutes for rare. If you wish the fish cooked to medium, leave it in for a few more minutes.
Meanwhile, make the tomato relish: Mix the tomato, onion, chives, salt and salsa together in a medium bowl. Add the lime juice and olive oil and mix well.
Remove the tuna steaks from the oven and spoon the sauce liberally over and around them. Serve immediately.