Put the chopped quince and apples in a saucepan with a splash of water or cider. Simmer until soft, then run through your food mill for a smooth, thick purée. Cool.
In a huge bowl, combine the dried fruits, peel, sugar, spices and suet. Add the citrus zest and juice, then fold in the cooled quince–apple purée. Stir well.
Cover the bowl and leave it in a cool place for 24 hours, giving it a stir once or twice.
Next day, stir in the calvados (or brandy). Spoon the mixture into sterilised jars, pressing it down firmly. Seal.
Store in a cool, dark cupboard. Every few weeks until December, open the jars and drizzle in a little extra calvados. By Christmas it will be sticky, fragrant and gloriously boozy.