Sonsie sauce

I've received a bottle of this in a gift hamper from Scotland and have never heard of it before.  Its a thick flour and vinegar sauce flavoured with mustard and various spices - not a million miles away from a piccalilli sauce.

Anyone else tried it or made it?  I'm thinking it would be good with sausages or chops 

I only know the word in relation to "yer honest sonsie face" in Burns' address to a haggis. The word seems to have a number of meanings depending on what the user is trying to convey in a pleasant way, but in answer to your question that description does sound as though it would be good with sausages, chops or cheesy dishes.