Instructions

1. 1

   Peel the onions, cut them into thin rings and dust them with the flour in a bowl until the rings are lightly floured all over.

2. 2

   Heat half the clarified butter in a pan and fry the onion rings in batches over medium heat until golden brown and crisp. Then drain them on kitchen paper and keep them warm.

3. 3

   Cut into the rim of fat on the steaks several times so the meat does not curl up while frying, and pat the slices dry.

4. 4

   Heat the remaining clarified butter in a heavy pan until very hot and fry the steaks for about 3 minutes per side, so that the meat stays pink inside and reaches a core temperature of 55 °C. Only then season with salt and pepper and keep warm in the switched-off oven.

5. 5

   Pour the excess fat out of the pan, deglaze the roasting residue with the red wine and let it reduce almost completely, stirring.

6. 6

   Pour in the beef stock, stir in the medium-hot mustard and let the sauce reduce uncovered over medium heat until it is lightly thickened.

7. 7

   Take the pan off the heat and stir in the cold butter or margarine in small pieces until the sauce is glossy. Season with salt and pepper.

8. 8

   Arrange the steaks with the meat juices on warmed plates, coat them with the sauce and cover with the fried onions.