The sauce will hold for 30 minutes or so, but is best prepared just before serving.
- Preparation time: 10 minutes
- Cooking time: 15 minutes
- Total time: 25 minutes
• 2 x 150g rib-eye or sirloin steaks
• ½ tbsp olive oil
• 1 tbsp unsalted butter
• squeeze lemon juice, to taste
For the bearnaise sauce:
• ½ small shallot, finely diced
• 2 tbsp dry white wine
• 1 tbsp white wine vinegar
• 3 tarragon sprigs
• 1 egg yolk
• 75g unsalted butter, melted and warm
1 Start with the béarnaise: put the shallot, wine, vinegar and 1 tarragon sprig in a pan. Bring to the boil; simmer until reduced by ½. Discard the tarragon and transfer the reduction to a heatproof bowl; set aside.
2 Take the steaks out of the fridge at least 30 minutes before cooking. Heat a heavy frying pan over a high heat until smoking, then add the oil. Season the steaks and place in the pan, pressing down to sear. Cook for 2 minutes (for a steak that is 2cm thick; a little longer if it’s thicker, or less if it’s thinner). Turn the steaks, add the butter to the pan, and cook for another 2 minutes, spooning the butter over the tops of the steaks occasionally. Set aside on a plate and cover loosely with foil while you finish the béarnaise.
3 Add the egg yolk to the shallot reduction and set over a pan of barely simmering water (the base of the bowl should not touch the water). Add a pinch of salt and whisk together using a balloon whisk for 3-4 minutes, until it doubles in volume.
4 Take off the heat and pour in the butter, in a slow, constant stream, whisking as you go. Once it’s all incorporated, season with salt, pepper and a squeeze of lemon juice. Chop the remaining tarragon leaves and stir through before serving with the steak.