Perfect to serve with my Beer Battered Irish Stout and Caramelised Onion Pork Sausages. This mustard mayonnaise will keep happily in the fridge for up to one week. It literally takes minutes to make. However if you are in a hurry, simply substitute with one cup or 225 ml (8 fl oz) of shop-bought mayonnaise and stir in the juice of one lime along with the wholegrain mustard.

Makes about 1 1/4 cups or 300 ml (1/2 pint)

1 egg (at room temperature)
juice of 1 lime
1/2 teaspoon salt
a pinch of caster sugar
1 teaspoon Dijon mustard
1/2 cup or 120 ml (4 fl oz) olive oil
1/2 cup or 120 ml (4 fl oz) sunflower oil
3/4 cup or 175 g (6 oz) wholegrain mustard
salt and freshly ground black pepper

Break the egg into the food processor and add the lime juice, salt, sugar, Dijon mustard and half of the olive oil. Secure the lid and blend for 10 seconds.

Leave to stand for a couple of seconds, then turn on again at medium speed and pour the remaining olive oil and sunflower oil through the feeder tube in a thin steady stream. This should take 25-30 seconds.

Switch off the machine, take off the lid, scrape down the sides, and blend again for 2-3 seconds. Transfer to a bowl or a jar, season to taste and stir in the wholegrain mustard, then cover with cling film. Chill until ready to use.