Step 1

Place Infused Vinegar ingredients in a small saucepan over medium low heat.

Step 2

Simmer for 2 minutes, then remove from stove and let it stand for 5 minutes to infuse.

Step 3

Strain, pressing to extract as much liquid as possible. You should have around 1 tbsp of liquid. Cool 5 minutes before use.

Step 4

Place butter in a jug and microwave until melted (1 - 1½ minutes on high, but watch it carefully so it doesn't explode!).

Step 5

Stand for 30 seconds until the milky whites settle at the bottom (this is the milk solids) and clarified butter (golden part) sits above it.

Step 6

Pour off 175g / 3/4 cup of the clarified butter, discard the milky whites remaining. Use in this recipe while hot.

Step 7

Alternative: Just melt 175g / 3/4 cup ghee, which is the same thing as clarified butter.

Step 8

Place egg yolks, infused vinegar and salt in a tall, narrow container that the blender stick fits in all the way to the base. Blitz briefly to combine.

Step 9

With the stick blender going on high, slowly drizzle the butter in over about a minute.

Step 10

After all the butter is in, blitz for a further 10 seconds, moving the stick up and down.

Step 11

Thickness: Add 1 tablespoon water, then blitz to incorporate. Add more water as needed, 1 teaspoon at a time, until the Bearnaise Sauce is a thick sauce but loose enough to ooze across a steak, coating it thickly.

Step 12

Fresh herbs: Stir in tarragon and chervil.

Step 13

Using: Use immediately, or keep warm until required. I use a thermos – a good one will keep it warm for at least 1 hour. Use warm or at room temperature. See note for storing and reheating.