1 shallot, finely chopped
1 tsp fresh thyme leaves
Β½ tsp mustard powder
125²µ/4Β½΄Η³ϊ butter
125²µ/4Β½΄Η³ϊ cheddar, grated
100g/3Β½oz smoked back bacon, trimmed
2 tbsp sherry or madeira