Linguine with mussels, saffron and chilli

I made this dish whilst down in Cornwall recently. It's basically moules marinere served over pasta.  A great quick supper.
Serves 4

1kg live mussels
pinch of saffron
Handful of fresh flat-leaf parsley, torn up
1 white onion, finely chopped
1 red chilli, finely sliced
1 glass white wine
350g linguine pasta
olive oil, butter

Clean and de-beard the mussels, discarding any that don't open when tapped.
Heat the pan, and add a lug of oil and about 10g butter. Add the onion and fry until softened, then add all the other ingredients (except the pasta).  Cook covered for about 4 minutes or until the mussels have opened (discard any that have not).
Meanwhile, cook the linguine according to pack instructions. Dish up the pasta into warm bowls, and pour the cooked mussels and most of their cooking liquor over the top. Serve immediately with a chilled white Sauvignon Blanc.