This recipe is a different take on a fish pie – a simpler one, as fish pie can be quite an undertaking, and although the end result is homely and comforting, the manner by which it is achieved seems to dirty every pan in my kitchen and exhaust every one of my nerves. And so I wanted to make a less challenging version, one that was just as satisfying but easier to assemble. Fish and breadcrumbs are a natural pairing – from fish fingers to fishcakes – and the contrast here between the creamy soft filling and the crunchy topping is simply lovely. You can use any tinned fish you fancy and replace the veg or bolster it with sweetcorn or jarred artichokes.
First, make your cheese sauce, so it’s done and out of the way. Heat a little oil in a medium saucepan over low heat and quickly stir in the flour to form a thick paste. To prevent this from burning, I use the smallest hob ring and work quickly. Add a splash of the milk to loosen it, beating quickly. Repeat until all the milk has been worked into the sauce and it is smooth and lump-free. Add the cheese and mustard, and turn the heat up slightly to melt it, still stirring. Season with salt and pepper and set to one side to cool and thicken.
Open your mackerel, tuna, peas and carrots and drain each well. If either of the fish are in oil, instead of brine, strain it into a small jar and pop it in the fridge to use for cooking – it adds an umami (savoury) base to onions for puttanesca, for example, or for frying fish in. I keep all of mine in neat little jars like sentries in the fridge door, labelled with the date of decanting, and instructions to use within 2 weeks. Add the fish and vegetables to the cheese sauce in the pan and fold through gently.
Grate the bread into crumbs, or pulse in a small blender if you have one. Spoon the fish, veg and sauce into a small ovenproof tin – a 450g loaf tin or 20cm cake tin is perfect. Top with the breadcrumbs and sprinkle lemon juice on top. Finish with a very generous scattering of black pepper.
Will keep in the fridge for 2 days, covered, or freeze in portions in freezerproof containers for up to 3 months. Defrost completely in the fridge overnight, then microwave to piping hot throughout to serve.
© Jack Monroe, 2020