Coat each tuna steak with wasabi paste and dip the coated steaks into the sesame seeds on both sides.
Heat up a cast iron skillet over medium high heat. Put 1 tablespoon of pecan oil per tuna steak, If your pan is large enough for both steaks use 2 tablespoons of pecan oil. Pan sear the tuna steaks, 3 minutes per side for medium rare.
Season with soy sauce and serve with lemon wedges, enjoy!