Pat the tenderloin steak with the crushed black peppercorns and
the olive oil and then place on a hot grill or in a hot skillet.
Cook on 1 side for 2 minutes and then turn and cook on the other
side for 2 more minutes to seal the steak. Continue to cook the
steak to your liking (rare, medium, well) by turning the steak
1 or 2 more times and pressing lightly on top to maintain uniform
shape.
If you are using a skillet, remove the steak from the pan and
reserve on the side (if you are grilling the steak you will need
a sauce pan to prepare the sauce). Sauté the chopped shallots
in the butter until lightly brown, add the green peppercorns
and sauté 1 minute more. De-glaze the pan with the red
wine and reduce by half. Add the demi-glace and bring to as boil,
reduce the heat and season with salt and pepper.