Beef Fillet with Onions and Chervil-cream Sauce
For the beef, season beef with salt and pepper. Heat oil in a pan and sear the beef on all sides until browned. Roast in a preheated oven at 200°F (gas mark 3-4, fan: 180°C) (approximately 400°F/convection 350°F) for 20-25 minutes.
For the sauce, heat 1 tablespoon butter in a skillet, add flour and cook until foamy, stirring constantly. While stirring, pour in broth and cream. Simmer 2-3 minutes. Season with salt and pepper. Peel onions and cut into rings. Heat remaining butter in another pan. Add onions and cook until browned. Rinse chervil, shake dry and pluck the leaves from the stems. Stir onions and chervil into the sauce. Let beef stand 5-10 minutes before slicing.