The fish might be workable but re-heating fully cooked fried potatoes in chip or fry formats is not usually very successful as the skin becomes harder, tougher and more leathery. Re-heated French fries are generally god awful.
Well gosh, sorry. I’m not convinced that making a quick sauce and mashing up the chips is so much more work than double-bagging and reheating in a pan of water, but OK. I don’t buy fish and chips to get out of cooking, I buy them because they’re delicious, but in all my (many) years of eating them, I’ve never found a way of reheating them exactly as they are which wasn’t a disappointment. You asked “Is there a way to do this without it turning out thoroughly gross? If so, what is the best way to do it?” and “Does anyone have any experience of doing something like this that enables them to reassure me otherwise, and can anyone offer any tips as how best to go about it?”. My experience is that reheating them will not be a happy culinary event, and it is better to slightly change their format.
I’d like to know which chippy you go to (so I can avoid it) and/or where you’re buying your ingredients (so I can go there too) that you can get, retail, a piece of fish of the size and quality provided by a decent chippy, plus all the other bits of the fish supper, for less than the cost of two meals’ worth of fish and chips.
Damn, ninjad!
Or fish croquettes - peel the batter off the fish, toast it until dry enough to turn into crumbs [or not] and flake the fish, add crumbs, a dab of mayonnaise to moisten and bind, roll in egg then in crumbs and bake in an oven, shallow fry in a skillet - I personally do both depending on my mood. You can also beat an egg and split the amount between using it in the filling to bind and to roll the croquette in to adhere the outside crumbs. You can also make patties instead of croquettes and fry up in a little butter without the outer layer of crumbs.
Or third choice, if it is cod, haddock or some other nice thick white fish - take a small onion and chop it, along with a couple ribs of celery, and a peeled carrot [I will slice the carrot and celery almost paper thin so they cook fast] Take a couple rashers of streaky bacon and chop up, then start frying until you get enough fat in the pan to sautee the veggies slightly. Take a potato about the size of your fist and peel. Slice into moderately small dice, about 1 cm cube. Add to the pan, and cover with just barely enough chicken broth to cover. Add a large pinch of thyme and as much black pepper as you feel it needs. Cover and simmer briefly, while you peel off the breading from the fish. Take the lid off and poke with a knife tip to see if the potatoes are cooked through but not mushy. Take 1 cup of full fat milk and a tablespoon of corn starch not meal and mix into the milk thoroughly, then stir into the soup and turn the heat to the lowest setting, and drop the fish into the soup in large chunks and cover and simmer for about 2 minutes until the fish is reheated. When you pour it into your bowl and stir, it will break the fish up into smaller pieces. Adjust any salt and pepper to taste.
[this is for one large hungry person type serving. If you want to use a half kilo filled of raw cod, it is 2 large carrots, 3 ribs of celery, a softball sized onion, 4 to 6 rashers of bacon, half a tbsp of thyme, a quart of chicken stock, 2 cups of milk and 3 tbsp of corn starch and makes 4 moderate servings.]
What I do for pizza slices, and it might work for what you have in mind.
I get my cast iron frying pan very hot, with a wire rack in the bottom to keep the pizza slice above the surface. I put in a few tablespoons of water, and cover the pan and let it stand for a few minutes. The water keeps it from drying out, and it heats through thoroughly. Too much water, and the steam will make it soggy, so it might take a bit of experimentation.
Reheated chips are just not the same. We reuse leftovers by chopping then up and putting them into a frittata. Pretty good that way and quick.
Pitch the chips. Eat the fish cold.
astorian is right - I’ve never found a way to salvage them either. What you describe above (reheating the fish, and making your own new batch of chips) is what I’d do.
If we’re talking about repurposing, my recommendation would be tuna salad sandwich using cod or whatever fish was in the left overs. Take off the breading and break it up, using the same recipe you’d normally use for tuna salad. (Mayo, celery, relish, for me.)
Then I’d use the chips/fries in hash browns for breakfast. It’s the only use for leftover fries I’ve tried that works for me. They crisp up nicely and the fact that they already have some oil on them means you don’t need to add much to the pan.
Maybe it’s just the way I like them (I prefer “soft” chips to “crunchy” ones), but I have never had a problem with reheating chips/fries in a microwave. (In fact, the way I usually make them at home is, cut a potato up into chips, toss with 2 tsp of olive oil, and put in the microwave for about 8 minutes. No, they’re not crisp.)
Fried fish - and chicken, for that matter - is another story; the microwave makes it rubbery.
Weird, everyone being unsuccessful at reheating the fries. I just put them in the convection toaster oven with the fish. Sometimes they come out extra-crispy, but that’s OK. I like extra-crispy fries. Sometimes I’ll eat them with catsup. Sometimes with tartar sauce. Or just plain, if they’re super-crunchy.
They heat just as well if I put them in the toaster oven without the fish. If I do that, they’re probably going into a burrito.