Season the steaks well with salt and pepper. If wanting to encrust the steak with peppercorns, see chef notes.
Add the oil to a large frying pan over high heat and heat up until it begins to lightly smoke.
Place in the steaks, turn the heat down to medium-high, and add in the butter, garlic, and thyme and cook for 2-3 minutes per side for a medium-rare internal temperature.
Remove the steaks and let rest on a plate. Drain the oil from the pan.
Sauce: Add the butter to the pan over low to medium heat and lightly sauté the shallots, garlic, and peppercorns for a few minutes or until lightly browned.
Deglaze with the cognac and cook until it is almost gone.
Pour in the cream and cook over low to medium heat until it becomes very thick, or nappe.
Season with salt and parsley and serve the sauce with the steaks.
Make-Ahead: This recipe is meant to be served as soon as it is finished cooking.
How to Reheat: This recipe does not reheat well, but if you do need to reheat it, then re-sear it in a hot pan with lightly smoked oil until warmed.
How to Store: Cover and keep in the refrigerator for 3 days. This recipe will not freeze well.
If you want to make this recipe where the steak is coated in peppercorns, simply encrust the steak after seasoning it with salt in the peppercorns that were broken down with the pan, and then obviously the cream sauce will not have any peppercorns. This part is up to you.
Cognac is the better option to use over brandy, but brandy can be used.