I made one of my favourite inventions/recipes. I made this up shortly after I left home at the age of 16, and needed something easy and cheap to eat that wasn't takeaway. So here it is:
Take one bag of instant potato. Or 4 cups of mashed potato if you've got it. But I rarely do so I have been known to use any kind of brand of instant potato. Sue me for being trashy - it's the only time I've ever used it. Make it up with a little less than usual liquid as you need it to be stiff.
Take a 250g packet of frozen spinach and cook it as instructed. Don't squeeze the extra out but it shouldn't be Wet.
Take 1/2 an onion and brown it up in a bit of oil in a frying pan.
Drain a small ish tin of tuna.
Mix all of this in a bowl. Add a good handful of grated cheese, some salt and pepper, and an egg.
Pat together into little patties and in an ideal world, leave in the fridge for 1/2 hour minimum. If you're in my house and you want to eat them NOW, heat the same frying pan with a smidge of oil in it, and pan fry gently until crispy. I find you don't need to put flour or breadcrumbs on this, to keep them together or to get them to crisp up. You can pat them in something if you want - breadcrumbs with chili flakes, or parmasen cheese.
Eat. Eat cold. Put it on a roll or in a salad.
These are gluten free as made if you get gf potato or make it yourself obviously. You can make them without cheese and/or egg but reduce the water content when making the potato. You may need to rest them to do that as the egg and the cheese both bind the mixture.