XO Chilli Sauce

First time I've come across this so I thought I'd pass it on. Twenty years ago or more the chinese restaurants in Hong Kong started to compete with each other to make the king of chilli sauces. Named after XO Cognac - the house best traditionally kept for the patron - this sauce is supposed to be excellent with fish or shellfish but can be used on anything.

4 Dried scallops (aka conpoy) soaked in warm water for 2 hours
50g dried shrimp soaked in warm water for 2 hours
200g long red chillies deseeded and finely chopped
50g fresh ginger finely chopped
50g garlic finely chopped
2 tsp salt
2 tsp sugar
300ml vegetable oil
3 spring onions finely chopped

Steam the soaked scallops for 10 minutes then shred while warm. Pound the dried shrimp to a paste in a pestle & mortar.

Put all ingredients except spring onion in a pan and cook on a low heat for 45 minutes. Allow to cool and add spring onions.

I've not made this yet - the hunt is on for dried scallop - if anyone has tried it, do you know how long it will last?