If you are going to use olive oil, use the "light" processed olive oils, as extra-virgin olive oil will smoke when brought up to a suitable temperature for searing. I prefer sunflower oil as it has a high smoke point and juetral flavor. It will let the flavor of the steak shine.
Lard also works well for searing, but is generally frowned upon by most in our hemisphere as an unhealthy fat. If you do just a bit of research into fats, you will find a great controversy about what constitues a healthy and un-healthy fat. So use at your own discretion. I know that it has less cholesterol than does butter, and is much healthier than all trans-fats, such as margerine, and shortening. It also has superior flavor than the artificial fats.
Seeeeeeya; Goodweed of the North