Put fish stock in a small frying pan and add saffron and lemongrass. Set pan over a very low heat and infuse for 12 minutes. Add white wine, then increase heat to medium-high and reduce to 150ml (pour into a jug to measure). Cool.
Scrub mussels under running water and soak in a sink of warm water for 10 minutes. Pull out the beards. If the mussels appear gritty, soak briefly again. Put wet mussels in a large saucepan, cover and heat over medium-high to steam until they open. Transfer to a bowl as they open. When cool enough to handle, open mussels fully and discard one shell of each. Keep mussels moist with a little of the cooking juices and cover with a plate.
Put reduced stock in a small frying pan and remove lemongrass. Add cream and reduce until like thick pouring cream. Turn off the heat.
Heat a medium frying pan over medium heat and add the butter. Once it is sizzling, add the crumbs and cook until starting to brown. Add lime zest and garlic and continue cooking until golden. Season with a pinch of sea salt.
Arrange the mussels on a platter and then spoon over the saffron and lemongrass cream. Top with toasted crumbs and serve.
Lemongrass and lime add bright flavours to these delicious mussels. Serve on plates to catch the tasty crumbs, accompanied by bread.
To prepare ahead
Steam mussels, keep covered and moist in the fridge. Make saffron and lemongrass cream, refrigerate and loosen if necessary in the microwave before using. Toast crumbs.
Article from the November, 2011 issue of Taste magazine.