Make the rub: combine the garlic, thyme and salt in a small bowl.
Rinse and pat dry the tuna steaks. Sprinkle enough of the rub on one side of the tuna to coat, and gently rub it into the fish. Turn the tuna over and repeat on the other side.
Make the olive relish: Combine the olives, olive oil, lemon juice and parsley in a small bowl. Set aside.
Coat a a nonstick skillet with oil spray on medium high heat. When it is hot, add the tuna and cook for 90 seconds on one side. Turn and sear on 90 seconds on the others side. Remove from heat.
Plate the tuna steaks, and top with the olive relish. Enjoy with a full bodied rosé wine if you are so inclined.