gluten freeHeat the oven
Preheat the oven to 180° C. Place a heavy ovenproof pan or baking dish on the bench so it is ready for the cabbage.
Prep the vegetables
Rinse the Cabbage if needed, then pat it dry well. Trim off only any rough outer leaves or a very thin slice of the base, leaving enough core intact so the pieces hold together. Cut it into wedges or thick slabs. Thinly slice the Shallot, and lightly crush the Black Peppercorns with the side of a knife or in a mortar so they crack open but are not powdered.
Season the cabbage
Set the cabbage pieces on a tray or board, drizzle with Olive Oil, and season generously with Salt and Black Pepper. Turn the pieces so the cut sides get coated too.
Char the cabbage
Heat the ovenproof pan over high heat. Lay the cabbage in a single layer and cook until the first side is deeply charred and smoky-looking, adjusting the pieces as needed for even contact with the pan. Turn the wedges over once the underside has strong color.
Roast until tender
Transfer the pan to the oven and roast the cabbage for 30–40 minutes, until the outside is well charred and the centers are completely tender when pierced with a knife.
Season the steak
While the cabbage roasts, pat the Eye Fillet dry with paper towel, then season generously all over with Salt (to season) and Black Pepper (to season). Let it sit at room temperature while you heat the pan so the seasoning adheres and the surface dries slightly.
Sear the steak
Heat a little Olive Oil in a heavy pan over high heat until it shimmers. Add the steak and sear the first side for 2.5–3 minutes without moving it, pressing very lightly for full contact if needed. Flip and cook the second side for 2–2.5 minutes for medium-rare, adjusting a little if your steak is especially thick or thin. Add the Butter to the pan, let it melt, then baste the steak with the foaming butter for about 30 seconds. Transfer the steak to a board or warm plate.
Rest the steak
Leave the steak to rest for at least 5 minutes before slicing so the juices can settle back through the meat.
Build the sauce
Lower the heat under the steak pan to medium. Add the sliced shallot and crushed peppercorns and cook, stirring, until the shallot softens and smells sweet and fragrant. Stir in the Dijon Mustard briefly, then pour in the Brandy, scraping up all the browned bits stuck to the pan.
Reduce and finish
Let the brandy cook down until nearly dry, then add the Beef Stock and simmer until reduced by about half. Pour in the Thickened Cream and continue simmering until the sauce thickens and reduces by about half again, enough to lightly coat the back of a spoon. Turn off the heat and whisk in the cold butter a little at a time until the sauce turns glossy and smooth. Taste and season with Salt (to taste) if needed.
Finish the cabbage
Take the cabbage from the oven. Drizzle over the Red Wine Vinegar while it is still hot, then shower with Parmesan.
Slice and serve
Slice the rested steak against the grain. Arrange it with the charred cabbage and spoon the peppercorn sauce over the steak or serve it alongside so the crust stays pronounced.
