When cooking steak, I have always been told groundnut oil is the best to use. But what difference does it make? Is it the best? And if it is the best, what's the next best?
The flavor is going to be the biggest difference when used on steak.
Different oils have different smoke points but for searing stake that doesn't make much of a difference because of the high temperature.
In New Orleans, steaks have been served in sizzling butter since before Ruth's Chris made it popular.
I never use oil to cook steaks. Why? There is natural fat on/in it already. If I feel I must have fat to keep from sticking, I trim excess fat off one bit and rub it over the heated pan. To keep steak from sticking to my pan, I usually season with dehydrated garlic and onion plus powdered or ground leaf spices. Those tend to stick slightly then I later use water mixed in with the stuck down spices to make an au jus for either potatoes or rice.
Here is how Gordon Ramsey does it (he uses groundnut oil (aka peanut oil), one flip, 2.5-3 mins a side, butter added mid way, sides cooked at end, feel only no thermometer) https://www.youtube.com/watch?v=rEx9gPhtjzs
Butter or spray oil contain emulsifiers which, according to McGee, prevent sticking.
Personally, I like refined peanut oil for searing steaks.
Here is a list of smoke points for various oils: http://www.goodeatsfanpage.com/collectedinfo/oilsmokepoints.htm
Due to their unstable chemical structure, polyunsaturated fatty acids are more susceptible to rancidity than saturated and monounsaturated fatty acids, especially after prolonged contact with oxygen, light or heat. Oils that are predominately polyunsaturated include walnut, grapeseed, soy, corn and fish oils. These are liquid at room temperature.
Many experts don't recommend polyunsaturated oils for cooking because they are so easily damaged by heat. They are best used in their raw form, and used quickly at that. Never keep polyunsaturated oils beyond their expiration date. If cooking is necessary, use low temperatures. Polyunsaturated oils should be stored refrigerated in dark bottles.
Furthermore, grain- or legume-based oils concentrate the toxins the seeds use to protect themselves against being eaten.
Clarified butter, coconut oil, beef tallow, butter and similar oils with low poly-unsaturated fat content are the best oils for frying or deep frying. No, they won't give you a heart attack.
Is ground nute oil the same as peanut oil?
I like to use peanut oil IF I am frying burgers instead of grilling them. It produces a wonderful flavor. Since burgers are ground steak per se, I would say it translates to steak as well, and I do indeed cook often in peanut oil.
My choice of oil however has more to do with what I am cooking beyond just the beef itself...i.e. more Asian style vs. Mediterranean style, but alone without the culture feel of the dish wishstanding, I like peanut oil best.