Season tuna steaks generously with salt and pepper. (optional: sesame seeds)
Pan: Place a skillet over medium-high heat and coat with 1-2 tablespoons of olive oil. Lay the tuna in the hot oil and sear for 1-2 min on each side to form a slight crust. Adjust time to taste and steak thickness.
Grill: Brush tuna with oil. Sear over high heat 1-2 min per side.
Serve with wasabi, ginger, soy and/or chili garlic sauce.