Room temperature beef loin lightly marinate 1 hour before cooking : sprinkle with salt, pepper, fresh rosemary, honey and olive oil.
2
Cut into pieces about 1.5cm thick. Prepare gratin: heat butter on a frying pan, add finely chopped onion. Fry until golden over medium heat. Add salt, sugar, some drops of cognac or whiskey.
3
Add sliced brown mushrooms, cook until golden brown colour 5-7min. Add fresh cream and warm up well, add salt and with pepper. Then add grated Parmigiano and little of black truffle.
4
Warm up and remove from the heat, add fresh greens. Warm up a little olive oil in the frying pan. Put the pieces of tenderloin on it fry several minutes on intensive heat until light brown crust from both side.
5
Transfer mignons into tray and pour with prepared wine-balsamic and bouillon reduction. Put spoonful of mushroom gratin on the top and cover with aluminum foil. Send fillets to preheated oven 160C for 8-9min.