This takes a while but is definitely worth the effort. I bought a selection of fish at the market this morning. A salmon steak, white fish steak (I have no idea what it is!) and a few king prawns only cost 6 euro and it’s enough for two meals.
For the mash: simmer cauliflower florets and diced butternut squash in whole milk until soft. Pour the milk into a bowl for later and mash then season the mashed vegetables.
For the fish stock: peel the prawns (if you don’t devein them you’re no friend of mine), chuck the heads in a saucepan and add a splash of white wine, a couple of bay leaves, a few peppercorns, a chopped carrot and chopped celery then cover with water. Bring to the boil, skim the foam off then reduce the heat and simmer for 5 mins.
I know it doesn’t look that appetising but it is really intense in flavour and, well, your not eating these bit anyway! So add the fish and prawns and poach for 4 mins. Remove the fish, strain the stock and throw the other bits away. Pop the stock back in the pan and simmer until it’s reduced by about half. (This is too much stock for one dish, maybe make a fish soup tomorrow?)
Make a parsley sauce either by using some of the mashed vegetables as a thickener or standard white sauce, no matter which you chose you’ll be adding fish stock and reserved milk until you’ve got the desired consistency and flavour. So lots of freshly chopped parsley in your sauce. Check seasoning and add a squeeze of lemon juice. Cool the sauce then combine with the fish.