The mustard enhances the concentrated mushroom taste.

8 medium mushrooms
25g very finely chopped onion
25g light oil
15g whole grain mustard
30g mayonnaise
Seasoning as required

1. Chop the mushrooms finely until there is no obvious white mushroom showing.
2. Heat the oil and fry the onion without colour for 30 seconds
3. Add the chopped mushrooms and cook until the mushrooms have changed colour and most of the moisture has evaporated. Do not overcook so the mixture begins to fry.
4. Cool the mixture until cold.
5. Add the mustard and mayonnaise and season to taste.
6. Chill until required but serve at room temperature to get the best flavour.