Preheat the oven to 60 degrees.
Take an iron pan and fry the steaks on butter each side for 3-2 minutes.
Add extra butter and chopped onion. Stir.
After the butter melted add the green peppercorns.
Pour cognac over the meat, onions and peppercorns. Take a long lighter and flambe the steaks. Don't worry, the alcohol will evaporate immediately, but the nice cognac flavour will stay.
Wrap the steaks with cooking foil and put into the oven for 5 minutes.
Add veal bullion, cream and salt to the same pan.
Let it simmer until the steaks are ready. Use beurre manier, if you are unhappy with the consistency of the sauce.
Take the steaks out of the oven and pour the juice from them into the pan. Mix the sauce very well and serve immediately.