>>21467797 (OP)>Olive oilFuck no. The smoke point of olive oil is highly variable over a wide range: 350-410° F (averaging around 375-80°) for virgin oils and 390-470° for refined ones. For searing steak we really want 450°+, and even "light" olive oil can't do that consistently without smoking; extra virgin oil smokes too low in any case.
Clarified butter (or ghee, if you prefer), beef tallow (if you can find it), and avocado oil (nutritionally similar to olive oil, but with a *much* higher smoke point) are the best options. All of these can go to at least 480° (avocado oil allegedly has a smoke point around 520°).
>Rosemary>>21468025>>21469674>thymeTarragon. Fresh tarragon in the form of tarragon butter (beurre d'estragon), dolloped on top of the cooked steak while it's resting. Beurre d'échalotes (with shallots) and beurre Maître d'hôtel (parsley and lemon juice) work well, too.
Alternatively, sauce béarnaise, sauce Roquefort, sauce marchand de vin (brown sauce with red wine reduction and shallots), and sauce aux champignons (mushroom sauce, with or without cream) are all excellent and classic with steak, and also simple enough to prepare at home.
>>21468358Save the duck fat for the potatoes, IMO. Like lard, duck fat has a smoke point around 375°, which is higher than non-clarified butter (around 325°) and the lower end of the range for olive oil, but while that is plenty hot for most pan-frying or sautéing, it's not hot enough to put the ideal crust on a steak.