Spiced up mussels, another variation

We've a house "Open Day" tomorrow, hence the paucity of food blogs, we daren't use the kitchen! But tonight the mussels were demanding something a bit more seasonally warming than just, say white wine and cream. So a spiced broth in which to steam them:
a glug of oil, two finely chopped small onions, a large splash each of fish sauce, white wine vinegar, lime juice, dry sherry: some larger than others depending on the result you want. A chunk of ginger, a whole but deseeded green chilli and a big handful of parsley and some lemon thyme add the spicy flavours.
Cook for 15-20 minutes and then leave to cool. Pick out all the stalky things before adding the mussels to steam. Serve with lots of finely chopped parsley (coriander would be even better methinks) and a splosh of sweet chilli sauce: maybe that's a glug too far, but this is November guys!