1kg potatoes, fresh or tinned
1 large onion
A handful of chopped fresh thyme
350g skinless river cobbler or other firm white fish
350g skinless smoked haddock
300ml whole milk, plus extra to mash the potatoes
50g hard strong cheese
30g butter, plus extra to mash the potatoes
2 heaped tablespoons plain flour
70g spinach leaves
A handful of fresh parsley
Preheat the oven to 180°C/350°F/gas 4.
Wash and dice the potatoes (or drain if using tinned ones) and bring to the boil in a large saucepan of water. Reduce to a medium heat and cook until tender – 20 minutes for fresh potatoes, 5 minutes for tinned.
Meanwhile, poach the fish. Peel and slice the onion and put into a large sauté pan or saucepan with the thyme. Add the fish, cover with the milk, and poach on a low heat for around 8 minutes. Remove the pan from the heat, take out the fish and onion pieces and place on a plate. Flake the fish with a fork. Reserve the poaching liquid to make the sauce with later.
Boil or poach the eggs in a small saucepan for 6 minutes. Drain and carefully spoon on to the fish plate. Check the potatoes – they should be very soft by now. When cooked, drain the potatoes and tip back into the saucepan. Mash with a little milk and butter. Grate the cheese into the mash and stir well to melt through.
Melt the butter in a milk pan over a low heat and add 1 tablespoon of the flour. Stir well with a wooden spoon to make a thick paste. Add the other tablespoon of flour and repeat. Now take a tablespoon of the reserved poaching liquid and stir it into the paste until well mixed in. Repeat, gradually adding more liquid, until blended together in a thick sauce. You may not need to use all the poaching liquid. Add the spinach, stir to wilt, then tip in the cooked eggs, mashing them with the back of a fork to break up. Add the onion then the flaked fish and mix everything together well to coat in the sauce.
Spoon the fish mixture into a large ovenproof casserole dish then top with the potato mash, starting at the edge of the dish and working inwards, using a fork to fluff up the top. Bake in the preheated oven for 20 minutes, until the mash is golden and crispy on top.
All recipes can be made with a budget of just £10 a week
Recipes extracted from 'A Girl Called Jack' by Jack Monroe (Michael Joseph, £12.99)