Heat source
Mustard fruits are a condiment originating in the north of Italy that is served with poached meats or grilled poultry and game. Most commercially available mustard fruits are predominately citrus and candied whole, but this same method can be applied to singular fruits such as quince or pear. In fact, any fruit with a high pectin level is suitable.
At this point in the year, when some fruits are approaching their peak and some are past – cherries long done, figs at the end of their season and pears and quinces just coming on – I find that it’s best to dry the fruit first, thus having a level of control over the moisture content and seasonality.
Macerating the fruit in the warm syrup will either extract liquid from fresh or allow absorption for dry, therefore creating some form of equilibrium across the spectrum. Avoid the temptation to use frozen fruits because freezing denatures the structure, which makes the fruit break down more when heat is applied.
The beauty of the mustard fruit is the play between sweet and hot. The mustard heat is very different to chilli heat and more akin to horseradish or wasabi where its hit becomes more olfactory. It’s heat in the nostrils that you either love or hate. This plays into many different applications and although I have already mentioned its predominant use with meats, the first time I came across it was in a dish of ravioli filled with pumpkin and mustard fruits served with sage butter and ricotta.
For a more pungent mustard fruit you can add mustard oil, but do be wary as a lot of the cheaper varieties use a synthetic compound. There is a good cold-pressed Australian product I have found available at most health-food stores.
If you are making the preserve from a single fruit such as pear, this is the point where I tend to play with flavours a bit more by incorporating spices. Fragrant pepper such as Kampot or green peppercorns works really well, as does saffron.
This style of mustard fruit is also excellent to blend as a base for a dressing on salad leaves.