Just before Christmas, Tito, who works in the kitchen at Petersham, returned from Italy with some mustard fruit. I had asked him as a favour to buy some and bring it back so we could use it at work. It's a sticky jam that consists of preserved fruit laced with mustard essence, which is traditionally served with boiled meat. What I hadn't banked on was Tito spending £800 on boxes and boxes of this delicious condiment. Green tomato, citrus and chestnut were just some of the varieties he brought.
The most prized variety is Mostarda di Cremona – from Cremona in Lombardy. Mustard essence is added to fruit cooked with high quantities of sugar. It has a very particular flavour that can tickle your nose and make your eyes water with its strength.
Mustard essence is not available to buy in this country through it is easy to find in Italy – sold in almost every chemist. I use mustard seeds and powder. You can use almost any fruit – apricots, pears, green tomatoes, cherries as well as chestnuts; although soft fruits such as raspberries and blueberries do not work as well.
Skye Gyngell is head chef at Petersham Nurseries, Church Lane, Richmond, Surrey, tel: 020 8605 3627, petershamnurseries.com
For the mustard fruit
Without mustard essence, here is a recipe that gets closest to traditional mustard fruits – it's not exactly the same, but still delicious. Serve alongside cured meats or hard, sharp cow's or sheep's milk cheeses.
Makes 4 250ml/8 fl oz jars
1kg/2lb fruit of your choice, such as pear, green figs or quince
500g/1lb caster sugar
11/2 tbsp strong mustard seeds
1 tbsp strong mustard powder
250ml/8fl oz white wine
The juice of one orange
Wash and pat dry the fruit, slice in half, remove the skin and cut into small pieces. Put the fruit in a preserving pan (or medium-sized pan with a heavy bottom). Pour the sugar over and add enough water to cover. Boil for 15 minutes, skimming off any white foam that comes to the surface. Cook until large bubbles begin to form and the jam begins to set. Test by placing a spoonful on a cold plate. It should just set but not be too thick.
Warm the mustard seeds gently in a pan until they begin to pop. Grind with a pestle and mortar to a fine paste. Mix with the mustard powder and place in a clean saucepan. Pour over the wine and orange juice and place over a medium heat. Stir to dissolve the powder and reduce by a third. Remove from the heat and spoon over the fruit. Mix well and place in well-sterilised jars. Allow to cool completely and place in the fridge. It will keep well for two weeks.
Poached guinea fowl with green sauce, boiled eggs and mustard fruit
The base for this dish is light and delicate; the green sauce and mustard fruit give it an intensity that otherwise it would not have. You can preserve everything beforehand, then simply poach the guinea fowl in warm stock before serving.
1 litre/13/4 pints home-made stock
3 fresh bay leaves
500g/1lb potatoes, such as Roseval, sliced in half with skins left on
3 carrots, peeled and sliced
2 fennel bulbs, tough outer leaves removed and cut into quarters
4 guinea fowl breasts, skins removed
Salt and pepper
For the green sauce
1 bunch of flat-leaf parsley, leaves only
1 bunch of mint, leaves only
1 handful of rocket
2 tbsp capers, packed in salt, well rinsed
2 tbsp red-wine vinegar
1 tbsp Dijon mustard
250ml/8fl oz extra-virgin olive oil
2 hard-boiled eggs
Mustard fruit of your choice
Place the stock into a heavy-based pan and bring to the boil. Immediately turn down the heat to a simmer. Add the bay leaves, potatoes and carrots and cook until just tender – this should take about 15-20 minutes. Put to one side while you make the sauce.
Using a sharp knife, chop all the herbs finely and place in a bowl. Roughly chop the capers and add to the herbs. Stir in the vinegar, mustard and oil. Peel the eggs and grate using the biggest holes on your grater. Add to the herbs and stir once again to combine.
Fifteen minutes before you are ready to eat, return the vegetables to the heat. Once simmering, add the guinea fowl and poach for 10-12 minutes. Adjust the seasoning – you will need to add a good pinch of salt, but not too much pepper, as the mustard fruit is very peppery.
Ladle into warm bowls, ensuring that everyone gets a little of everything. Spoon over the green sauce and pass the mustard fruit around separately.
Pan-fried fillet of beef with mustard fruit and chard
Mustard fruit is good with almost any meat – wonderful as an accompaniment to glazed ham or served simply, as it is here, with really good-quality, pan-fried beef.
1 bunch of chard
Extra-virgin olive oil for drizzling
A squeeze or two of lemon juice
Salt and pepper
1kg/2lb beef fillet
Sea salt and freshly ground black pepper
1 tbsp extra-virgin olive oil
Mustard fruit of your choice
Place a large pot of well-salted water on to boil. Rinse the chard under cold water. Once the water has come to a boil, plunge the chard into the water and cook for three minutes. Drain and, while warm, dress with the olive oil and lemon. Season with salt and pepper and toss well to combine.
Place a large, non-stick pan over a high heat on the stove. Season the meat generously. Add a little oil to the pan and when the pan begins to smoke, add the beef, making sure there is space around each fillet. Turn down the heat slightly and cook for six minutes, before turning and cooking on the under side for three minutes. Remove from the pan and allow to sit for 10 minutes in a warm place.
Divide the chard among four plates. Lay the beef alongside and spoon a tablespoon or so of mustard fruit on top of the beef.