- 2 tbsp white wine vinegar
- 1 tbsp parsley stalks, roughly chopped
- 1 tbsp chervil, chopped
- 2 free-range egg yolks
- 1 tsp English mustard powder
- 150ml/5fl oz light olive oil
- 150ml/5fl oz vegetable oil
- salt and freshly ground black pepper
- squeeze lemon juice
- Place the vinegar, parsley stalks and chervil into a small saucepan and bring to the boil. Simmer until the volume is reduced to one tablespoon of liquid.
- Strain the liquid through a sieve and discard the parsley and chervil.
- Place the egg yolks, mustard powder and infused vinegar into a food processor and blend.
- With the blender still running, gradually add the oils. Continue to blend the mixture until all the oil has been incorporated and the mixture has thickened.
- Season with salt and freshly ground black pepper and add a squeeze of lemon juice.
- Spoon into a small serving bowl and serve.