1.Cut each cumquat in half. Hold each half over a bowl and squeeze out the juice and seeds. Cut each half in half. Strain the juice, discarding the pips (the jam will set well enough without their extra pectin power).

2.Place the cumquats and their juice in a heavy-bottomed pan, and add enough cold water to cover. Bring to the boil, then lower the heat and simmer gently for one to 1½ hours or until the fruit is soft.

3.Add the sugar, stirring until dissolved. Bring the mixture back to the boil, and boil quite rapidly for about 15 minutes, watching like a hawk, stirring occasionally and skimming judiciously, until the marmalade reaches setting point.

4.To test, place one teaspoon of the mixture on a saucer and cool in the freezer for three minutes. If set, it will wrinkle when moved. Stir in the tequila, then ladle carefully into warm, sterilised jars and seal.

TIP:

Unopened jars will last six months, easy. Store opened jars in the fridge and serve on hot toast, with good cheese, or with crusty bread and labna.