Preheat oven to 180 degrees
Oil & season both sides of the cabbage
In an oven safe pan, char one side of the cabbage. Flip & place into the oven
Season both sides of the eye fillet
In a pan, heat the olive oil & cook one side of the eye fillet for 2.5-3 minutes, pressing down to get a good sear. Flip & cook for a further 2-2.5 minutes for medium rare
Add the butter, baste for 30 seconds. Remove from pan & let rest
In the same pan, sauté the shallots & peppercorns
Deglaze the pan with the cognac or white wine & cook until completely reduced
Pour in the beef stock, reduce by half then whisk in the dijon & cream
Let it thicken & reduce again by half, then turn off the heat & whisk in the cold butter, 5g at a time until glossy & thickened
Remove the cabbage from the oven, finish with a drizzle of red wine vinegar
Slice your beef
Serve all together
