To make good marmalade, it is essential to use fresh fruit. Last year, one of the cooks in the kitchen at Petersham made enough of the stuff to last the whole year – enough, in fact, that we were able to give it away; it makes a lovely present, so make more rather than less! I've not given exact quantities here, but you will see why as you read through the recipe.

Several Seville oranges
A little salt
Caster sugar

Thinly slice the oranges – leave the skin on but discard the pips. Boil a large pot of water, add the slices and cook for two minutes. Remove from the heat and allow to steep for 24 hours.

The following day, add the fruit and water into a preserving pan or stock pot one cup at a time. Bring to a boil, add the salt and to every cup of fruit, add a cup of sugar. Return to the boil and cook for 30 minutes.

To test whether the marmalade is set, place a flat plate into the fridge to chill. Spoon a teaspoon of marmalade on to the chilled plate and, if it is ready, it will immediately set like sticky jelly. Remove from the heat and spoon into hot sterilised jars.