Makes 250 g (9 oz/1 cup)

Mustard is a must in everyone’s cupboard. This recipe is for wholegrain mustard but you can simply add all of the mustard seeds before blending to make a smoother version.

40 g (1½ oz) black mustard seeds

60 g (2¼ oz) yellow mustard seeds

125 ml (4 fl oz/½ cup) white wine vinegar

1 teaspoon pure sea salt

juice of 1 lemon

Place the black and yellow mustard seeds in a non-reactive bowl with the vinegar. Stir to combine, cover, and leave overnight.

Put two-thirds of the seeds and all the liquid into a food processor or blender, add the salt and lemon juice and process to make a smooth paste.

Transfer to a stainless steel bowl and stir in the remaining mustard seeds until combined.

Spoon the mustard into a sterilised glass jar and seal with a tight-fitting lid. Leave in the cupboard for 1 month before you use it. After you open it keep the mustard refrigerated — it will last for up to 6 months.