Timing (for the Bearnaise Sauce only)
Prep time: 5mins, cooking time: 20 minutes, total time: 25mins
- Be careful not to overheat when whisking as this will cause the sauce to split. You should be able to touch the bowl with your hand without getting burned, otherwise the eggs will scramble.
- If the sauce appears to be on the verge of splitting, as indicated by a slight greasy appearance, take it off the heat and whisk in a dash of cold water.
- This link to Jamie Oliver's Hollandaise technique is very helpful.
For the Base:
- 30ml white wine vinegar
- 2 chopped banana shallots
- 10 tarragon stalks
- 5g black peppercorn
- 2 eggs yolk
- Reduced vinegar base
- 20g chopped shallot
- 5g finely chopped tarragon leaves
- 140g White Truffle Clarified Butter
- Black pepper and fine salt for seasoning
For the Truffle Potato Terrine:
For the Steak:
- Make a reduction by boiling the white wine vinegar, tarragon stalks, peppercorns and the 2 chopped shallots until reduced to syrup texture, around 30ml. Will take between 25-35mins depending on the shallowness of your saucepan and heat.
- Strain and press until you're left with juice only. Add the 20g chopped shallots, cover and allow to cool.
- Get a saucepan and a heatproof mixing bowl that will sit stably over the saucepan. Half-fill the pan with water and bring to a simmer. Turn down the heat as low as it can go while maintaining the simmering.
- Take the lid off the white truffle clarified butter and microwave for 10-15 seconds, until it melts.
- Place the egg yolks in your heatproof mixing bowl, which you should then place over the pan of simmering water. (NOTE: the saucepan HAS to be on a low heat, or the eggs will scramble.)
- Start whisking your eggs in an 8 shape, then whisk in your vinegar reduction.
- Keep whisking, and then start adding the melted truffle clarified butter by very slowly drizzling it in, whisking all the time, till all the butter has been incorporated. The result should be a smooth, thick sauce.
- Add the chopped tarragon and mix.
- Season carefully with sea salt and black pepper, and loosen if necessary with a dash of cold water.