Wagyu steak, duck fat chips and béarnaise sauce

Method

1. For the béarnaise reduction: place all the ingredients into a non-reactive saucepan and simmer until the liquid has reduced by half. Sieve the mixture into a clean bowl and discard the herbs and spices.

2. For the béarnaise sauce, place the eggs in a pan of boiling salted water and boil for 4 minutes (until soft-boiled), drain and peel the eggs.

3. Heat the butter in a pan until it reaches the "beurre noisette" stage (this means that it is golden-brown and has a toasty nutty aroma). Remove the butter from the heat.

4. Place the eggs in a blender or food processor, add 50ml of the reduction (you can save the remainder in the fridge and use it to make another batch of béarnaise sauce). Blend the eggs and the reduction, gradually adding the beurre noisette. Pour in the lemon juice and a little water to thin the sauce if necessary (it should be the same thickness as hollandaise sauce).

5. Pass the sauce through a muslin cloth into a clean pan, add the tarragon and salt and white pepper, to taste. Stir through the chopped shallot, gherkins and parsley, and set aside in a warm place while you fry the chips and steak.

6. For the steak: preheat a griddle pan until hot and brush the steak with oil. Cook the steak for 1½-2½ minutes on each side, according to your liking. Leave the steak in a warm place until you are ready to serve.

7. For the chips: heat the duck fat in a deep fat fryer to 130C. Cut the potato into chunky chips and fry for 6-7 minutes, or until cooked all the way through, but not browned. Remove the chips with a slotted spoon and drain on kitchen paper. Now increase the heat to 180C. Carefully plunge the chips into the fryer and cook until browned all over. Remove again with a slotted spoon and drain on kitchen paper.

8. Serve the steak and chips with the béarnaise sauce on the side - any béarnaise sauce you do not use should be used up on the day.