1 onion, peeled and quartered
4 cloves
2 blades fresh mace or heaped 录 tsp ground mace
1 fresh nutmeg, for grating
1 tsp white peppercorns
2 tsp salt
1 day-old loaf unsliced white bread
30g/1oz butter
2 tbsp double cream, optional
1 litre/2 pints full-fat milk