apparently they're all gourmet and fancy
I don't really agree about the "
they're all gourmet and fancy" part: where I'm from, many of canned fishes are terrible bottom-of-the-barrel stuff. However, with right seasoning combined with the type and brand that tasted right for you
(1), it can be a reasonably-good poor man's menu indeed.
But I noticed you were referring to "little
flat cans", so I'm not sure whether we are really talking about the same category of canned fishes or not. In my country, the most most common kind of tins for canned fish is a tall cylindrical tin which is substantially smaller than canned coffee can, another kind is a short-but-wide cylindrical tin of various sizes, and the rarest kind (exclusively the imports) is flat rectangular tin that opens on the top. I would be speaking mostly of the first kind which I had the most experiences with. (The second kind tasted the same, just bigger; except when it was tuna cans-- more on that later)
The most common run-off-the-mill type of fish in the cans around here is
mackerel in tomato sauce, and slightly less common one is
sardine in tomato sauce. (It's nearly always tomato sauce for some reason; I saw one in chili sauce once in a blue moon, and never any in brine unless it was tuna) I never liked eating them out of the can.
In last decade however, my mom taught me how to
make Thai salad out of these kinds of canned fishes; basically draining half of their sauce away, add some fish sauce, rice vinegar (or lime juice), chopped shallot, chopped long coriander, and liberal amount of ground toast chili. Mix them well, and serve with hot steamed rice... and holy seven oceans,
it's so lit! If I would have to describe the taste: it's
quite close to Thai tom yum curry, but much more fleshy and with thick, juicy, concentrated sauce.
Nowadays, I also found a way to make it into a sort of 2-in-1 meal: by using all of the sauce in the can, increase the rest of ingredients accordingly, and eat only half of this Thai salad for one meal; then put the leftover in the fridge. And on the next meal, make fried rice using this leftover Thai salad, spice it up a bit with small amount of seared chopped garlic, little more fish sauce and vinegar. Tada!
Nice and spicy Thai "tom yum" fried rice. I just had this as a dinner yesterday; and it tasted great, considering that it's a leftover cuisine.
The other other menu I deemed "nice enough" to make out of these canned fishes is fish tempura. It's quite tricky to make it palatable, since the tomato sauce left it with quite a strong stench that I don't like in tempura; so some carefully-tuned amount of chopped coriander root and/or garlic had to be added to the batter to camouflage the stench. Other than this menu, my mother likes making actual tom yum curry or Thai sour curry ("kaeng som") out of these canned fishes; which tasted okay, but they're not my favorite.
For tuna, here it always come in short-and-wide cylindrical tins, and I found that it's best when it came in brine. (It's just... yuck when it came in any kind of oil) In any case, canned tuna is one of the most expensive variety of canned fishes generally available around here. The last time I managed to get it for cheap, my mom cooked it into a bowl of tuna floss
(2), and it was quite good.
I think I have seen some canned anchovies here (specifically in in flat rectangular tin for some reason), but it's not very common and definitely not cheap; I have never tried it.
(1) The my current favorite (Thai) brand is called Three Lady Cooks by Royal Foods, which my favorite type their canned fishes is their
canned sardines in tomato sauce.
(2) It is an imitation of local pladuk fu menu ("ปลาดุกฟู", lit. catfish floss; but it's usually called "crispy catfish" in English), using canned tuna in lieu of catfish.