Season them well with salt and pepper ... butter directly onto the steak and fry for 2 minutes on each side. Cover loosely with foil, rest and keep warm. For the sauce, add the stock to a saucepan ...
Taste for seasoning and acidity and add salt, pepper and more of the reserved liquid if necessary. The sauce will keep warm ... Meanwhile, pat the steak dry with kitchen paper.
Sear this steak in oil with some salt and pepper, being careful not to cook above medium, and add any sauce you prefer. Anything fat-forward, such as browned butter and sage, a béarnaise sauce ...