Béarnaise sauce

Add the shallot, tarragon stalks, bay leaf, vinegar, peppercorns and white wine in a pan and bring to a simmer. Reduce until there is only 2 tablespoon of liquid remaining in the pan. Strain the liquid into a heatproof bowl

Add the egg yolks to the bowl with the reduction and set over a pan of boiling water - do not allow the bottom of the pan to touch the water. Whisk together, removing the bowl from the heat every 10 seconds so the eggs don't scramble

Whisk until the yolks have doubled in volume - it should become very light. Pour the warm clarified butter into the eggs in small additions, whisking to incorporate each time - if the sauce gets too thick, add a teaspoon of hot water

Remove from the pan so the sauce can cool down a little and slowly whisk in the rest of the butter. When incorporated and smooth, stir in the tarragon leaves and lemon juice. Season to taste and serve