Season the tuna steaks on all sides with kosher salt, white sesame seeds, and black sesame seeds,
Heat a non stick skillet over high heat with avocado oil.
When the oil is hot but not yet smoking, place the tuna steaks into the pan. Cook the tuna steaks for about 1 minute per side , depending on the doneness you prefer. I cooked mine for 30 seconds per side and I like mine pretty rare.