1	For spiced green apple, combine apple and ¼ cup vinegar in a bowl. Heat remaining vinegar, sugar, cloves, ¼ cup water and 1 tsp sea salt in a heavy-based saucepan over medium heat and bring to a simmer. Add apple mixture and chilli. Return to a simmer, reduce heat to low and cook gently, without stirring, for 1 hour or until liquid is almost reduced. Cool and store in an airtight jar in the refrigerator until required. Makes about 1 cup. Spiced green apple will keep for up to 1 month.
2	Place flour, butter, cheddar and nigella seeds in a bowl and using fingers rub butter through flour until it resembles coarse breadcrumbs. Add egg yolk and mix until combined. Turn dough onto a clean surface and knead gently until smooth. Form into a disc, wrap in plastic and refrigerate for 1 hour.
3	Preheat oven to 180C. Roll out dough onto a lightly floured surface until 3mm-thick and using an 4cm-diameter fluted cutter cut out shapes and place on greased oven trays. Form remaining dough into a ball, roll and repeat. Bake for 10 minutes or until golden. Cool on tray. Store in an airtight container for up to 1 week. Serve biscuits with spiced green apple.

Note Nigella seeds add a sharp and nutty flavour. They’re available from Herbie’s Spices, select greengrocers and delicatessens. If unavailable substitute with cumin seeds. Spiced green apple can be substituted with a good-quality fruit chutney.