This is a surprisingly simple yet one of the best ways to cook fish steaks including those of tuna, king mackarel and salmon. Wash the steaks under running water. Use a paper towel to absorb any excess water remaining on the fish. Heat 2 - 3 tablespoons of olive oil in a non-stick pan at medium heat. Place the steaks on the pan. Sprinkle them with oregano and sea salt. Grill one side of the steaks for 10 minutes. You can keep the lid on to keep your stove top clean. Turn the steaks over, sprinkle them again with oregano and sea salt. Grill for 6 more minutes.