Get some saltwater barra, not the freshwater stuff.

Peel a sweet potato, roughly chop it equally and boil it in salted water until tender enough to make a mash.

While that's done heat your favourite oil (or butter if you want to go unhealthy), add some salt and pepper then add the barra fillets when hot, turn after 3-4 minutes then serve them on a sweet potato mash which is just the drained sweet potato with some butter, salt and pepper mixed in. I also mix in some baby spinach leaves, roughly chopped.

For a bit of zing you could try chilli oil, which is 20 birds eye chillies chopped per cup of oil, with six or more cloves of garlic chopped per cup of oil, and a teaspoon of paprika, heat but don't burn for 15 minutes then allow to rest for two days covered with clingwrap (to infuse the flavour through the oil), then bottle in sterilised jars (google it) and put in the fridge. If using the oil just drizzle a teaspoon or so accross the top of the barra, the orangeish colour adds to the presentation.

enjoy!