I have been using my cast-iron skillet for some time with good results.
Essentially, I bring out the meat from the fridge with time so it gets at room temperature, then I heat up my pan until it smokes and then I place the meat (with some salt and pepper and a little bit of oil) and cook it so it comes out medium-rare.
My issue is the temperature of the meat. As soon as I let it rest for 5 minutes after cooked, the meat cools down and it's no longer hot. I assume, since it has only been cooked for 3 minutes per side, that explains how fast it gets cold.
Is there any solution for this? How do restaurants do to keep the meat warm when it gets to your table?