Season the steaks on both sides with salt and pepper. Chefs use the trick of salting from above the steak so the seasoning spreads evenly.
Heat an iron skillet over medium-high heat, add the oil, then add the steaks.
For medium rare, cook for 5 minutes on each side.
Remove the steaks to a plate
Tent with aluminum for 5 minutes per inch of steak.
Lower the heat under the skillet to low.
Place the butter in the skillet and let it melt.
Sprinkle the shallot around the steaks and cook until softened (about a minute).
Add the beef bone broth and whiskey to the pan, turn up the heat to medium
Bring the sauce to a gentle boil.
Keep simmering until it reduces by half.
Turn down the heat to low.
Add the cream and stone-ground mustard to the pan.
Stir and let the mixture simmer until the sauce thickens slightly.
Serve the steaks with sauce drizzled on top. Sprinkle with chopped chives for garnish.