Cod is hard to describe. It’s so ubiquitous or so rare or endangered or somehow so obvious that I hadn’t really thought of it before now (except in batter). ‘Local cod’ said the sign outside Paul’s Plaice, the only fishmonger left in Seaford, and then you go through the little chain-mail curtain into a shop that smells of the sea.

Paul works alongside his brother and I’ve never worked out which one is actually Paul, although it’s been explained to me enough times. I just draw a blank. Perhaps my brain has discounted it because it needs to stay alert for ‘novelties’ such as an oncoming car or a mountain lion. Apparently this is what the brain does, it has this discounting mechanism which I read about in mad, brilliant novel Where’d you go Bernadette. I have also discounted the sea which roars all through the day and night outside my window. Every day it lies there, a different colour, doing something slightly different with itself; occasionally it catches me and I notice it – a thin pencil line on the horizon or a big mushroom cloud of rain the same gunmetal grey as the waves, gulls flapping over a fishing boat like washing on a line, something suddenly surfacing – a snout? – and then going under. Then I forget.

Back in Paul’s Plaice, I notice a box of tiny fish as small as matchsticks with the name Smelt written above, which I think sounds rather Dickensian. They’re baby whitebait, according to ‘Paul’. They look too small to taste of anything, too fragile, almost pre-fish. They also have local plaice and cod, and everything is from the nearby fishery. They’re caught trawler style, because netting taints the fish with all the seaweed that gets caught up with it. What about line-caught, I ask him. ‘That’s just a bloke standing there with a fishing rod’, he says. ‘I can get it for you but it’s really expensive.’ I know from past experience that my mother has got mackerel for free by walking past a full bucket at just the right time, but obviously this takes a certain louche opportunism that is beneath Paul, who I can only describe as ‘bubbly’ though I know that makes him sound like an Avon lady. They are all so friendly in there it’s quite disconcerting.

I cooked the cod and let me tell you it was so flipping good I went out and bought another three pieces, and ‘Paul’  thrust a whole handful of parsley into the bag for good measure. It was meaty yet tender, and chunks dissolved, not actually like butter, but with a gentle yielding buttery quality. I baked the cod in one of those parchment parcels, where it steams but also seals without drying out. You want the cod to somehow give itself to you, each layer opening, each cavity glistening, the smell of lemon and salt and heat and herbs, pale discs of pearly white, soft and supple. I think I’ll stop now.

Cod in a bag

With advice from Paul

Serves two

2 pieces of cod fillet, cut from the thick end (3 cm/1½ inches thick)

Olive oil & a small pat of butter

Lemon juice and the rind of 1 lemon

Sea salt

Fresh parsley (about four healthy sprigs)

Parchment paper

Butcher’s twine

Preheat the oven to 180C/350F. Arrange 2 sheets of parchment paper on a baking tray about double the size of each cod fillet. In the centre of the sheet put the cod and add what you like: here I added a pat of butter, some fennel fronds, a little glug of olive oil, a squeeze of lemon juice, the lemon rind cut thickly and some sea salt. But you can add anything; bay leaves, thyme, chillies, garlic, thinly sliced potatoes etc. Pull the corners of the parchment paper together and twist shut.  Secure with some butcher’s twine. Slide the tray into the oven and bake for about 15-20 minutes. Open the bag to check it’s done and sprinkle the insides with chopped parsley.