Crush the black peppercorns using a mortar and pestle or a rolling pin.
Spread the crushed peppercorns evenly on a plate.
Press each side of the filet mignon steaks into the crushed peppercorns until well coated.
Season the steaks lightly with salt.
Heat a medium skillet over medium-high heat.
Add butter and olive oil to the skillet, allowing them to melt and combine.
Once the butter is melted and the skillet is hot, add the steaks.
Sear the steaks for about 4 minutes on each side for a medium-rare cook.
Transfer the steaks to a plate and cover to keep warm.
In the same skillet, add the Cognac.
Carefully ignite the Cognac to burn off the alcohol, then let it reduce by half.
Add the heavy cream and simmer until the sauce thickens.
Return the steaks to the skillet, spooning the sauce over them before serving.