01 -
Allow beef fillet to reach room temperature. Trim the wider end to create two evenly sized pieces. Secure each with kitchen twine for uniform cooking and season generously with salt and pepper.
02 -
Preheat oven to 200°C. Sear the fillet pieces on all sides in a large frying pan over high heat until a deep golden-brown crust forms.
03 -
Transfer the seared fillet to the oven. Roast for 25 minutes for medium rare or 30 minutes for well done. Internal temperature should reach 55°C for medium rare, 57°C for medium, and 60°C-63°C for well done.
04 -
Remove fillet from oven and rest uncovered for 10-15 minutes. During rest, internal temperature will increase slightly and juices will redistribute.
05 -
Melt unsalted butter in a small saucepan over gentle heat. Remove from heat when foaming begins. Separate the clear yellow butter from the white solids, discarding the sediment.
06 -
In a small jug or beaker, blend egg yolks and white wine vinegar using an immersion blender until pale and thickened.
07 -
With the blender running, gradually add hot clarified butter in a steady stream, blending until sauce is pale and thickened. Fold in chopped tarragon and season with salt. Keep warm for serving.
08 -
Slice beef fillet and serve immediately with warm Béarnaise sauce.