Upside Down Fish Pie, 97p | 15 Minutes | One Pan | JACK MONROE

I’ve wanted to develop this idea from a mad little kernel in my wild head, into a fully fledged recipe, for several years now, and I’m delighted to finally share it with you. It’s all the fun and flavour of a fish pie, in 15 minutes, in one pan, and it’s an enormous hit in my household. Especially with me, because I do the all of the washing up. It’s not made in the traditional way, and I’m sure that there will be some ruffled fins somewhere about the sacrilege of that, but for the convenience and speed and general simplicity of it, it’s worth upsetting a few people. They’re not exactly breaking my door down to scrub my pans anyway.

Serves 4 generously, from 97p each. Prices costed at Asda and correct at time of publication.

300g white fish, £1.79 (£5.95/1kg, Frozen For Freshness)

2 medium onions, around 200g, 13p (65p/1kg, Growers Selection)

2 stalks of celery, around 120g, optional, 11p (50p/540g, Growers Selection)

2 tbsp light cooking oil, 5p (£5/3l vegetable oil)

A generous pinch of salt, <1p (30p/750g table salt

200g mixed frozen vegetables, 25p (£1.25/1kg, Frozen For Freshness)

1 tbsp flour, <1p (55p/1.5kg plain flour)

1 chicken or vegetable stock cube, 5p (60p/12 stock cubes)

1 tsp mixed dried herbs, 3p (35p/18g, Just Essentials)

600ml milk, 41p (69p/1litre UHT Skimmed Milk, Smartprice)

Plenty of black pepper, <1p (£1/100g, TRS)

80g cheese, 36p (£3.65/825g mature cheddar, Just Essentials)

120g powdered instant mash, 53p (80p/180g)

50g butter or soft spread, 15p (75p/250g Best For Baking block)

First pop your fish out of the freezer the night before and place it in a food safe bag, container or covered bowl in the fridge to defrost. Add the mixed frozen veg too if you like, but it’s much of a muchness as they’re already cooked, so if you don’t at this stage, they’ll be fine later on.

When the fish is defrosted and it’s dinner time, take it out of the fridge and set it to one side.

Peel your onions and dice or finely slice them, and slice your celery. Pop them in a large nonstick pan, and add the oil and a generous pinch of salt.

Place the pan on the highest heat on the largest hob ring, and fry your veg for 3 minutes, stirring occasionally to disturb them so they cook evenly and don’t stick and burn at the bottom of the pan.

Add your mixed frozen veg, and cook for 2 minutes more.

Sprinkle over your flour, crumble over your stock cube, and add your herbs, and stir these in well, so the veg is all very lightly coated, or as much as you’re able to.

Pour over a little of the milk and stir in briskly and well so that it forms a thick paste along with the flour and oil that are already in the pan. Add a splash more, stirring continuously, until half of the milk – 300ml – is incorporated into the pan.

Add your fish and fold in carefully so it doesn’t break up and flake too much, making sure it is covered by the liquid sauce.

Cover your pan with a lid, or if you don’t have a lid, a larger pan upturned to make a Dutch oven type thing, a baking tray laid flat across the top, a sturdy dinner plate that will withstand some heat, or some cooking foil will do the same job. Reduce the heat very slightly so it’s not absolutely boiling, and cook so the fish poaches through, which should take around 8 minutes. Stir in the cheese at the end to melt it into the sauce – you can reserve some for the mash if you’d like to.

Towards the end of the cooking time, pour the remaining 300ml milk into a microwave safe jug. Add 300ml cold water, then add the butter or spread, and the instant mash, and stir well to combine. Microwave on full power for 1 minute, remove and mix well with a fork to break up any lumps, and return to the microwave for another minute on full power. Remove and stir again.

Serve the mash in bowls and spoon the fish ‘pie’ filling generously over the top. Season with plenty of black pepper, and serve.

TO KEEP: Store any leftovers in a food safe jar, container or bag in fridge or freezer. Use within three days if stored in the fridge, or use within three months if stored in the freezer. Defrost overnight in the fridge and reheat to piping hot to serve.

All text copyright Jack Monroe, not to be reproduced without the explicit written permission of the author.


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  1. Love this Jack. Always steered clear of doing a fish pie style meal because all the recipes seemed far too involved for my meager skills. This one I CAN DO!

  2. This is a brilliant idea. I can’t see where you add the cheese though. I presume you put it in the mash? I think I’ll give this a try next time I pick up some reduced microwave mash.

  3. Thanks for this – it is similar to something I have been doing for a while, although I normally chop up a raw potato and microwave it for about 6 minutes before mashing it!
    Please don’t take this as criticism, but there is a typo in the first line of instructions – food sage bag – and there is no mention of the cheese going into the dish.
    Keep up the great work – you are much appreciated.

  4. Love this fish pie recipe Jack. Thank you your recipes are such a help. I have to swap out some of the ingredients as I hace coeliac disease ans can’t get to an Asda but you really help to stretch my budget.
    Blessings to you and small boy. X

  5. Being vegan(ish!), I don’t do fish, but going to try this using chopped Tofooo tofu, which was about £2 for a block enough to feed 4 last time I bought any, so doesn’t add much to the cost. Also, will be using soya milk, (I prefer this anyway) and a little bit of dried seaweed because I’ve got some, but wouldn’t bother me if i didn’t have it.
    Thanks for all the lovely recipe ideas, Jack, don’t know what I’d do without you and your books.

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