Just getting back to the OP: another vote to just add the stuff. You won’t taste any “rotten fish” taste, and if you are put off by the idea of things being “off”, then remember that you probably eat cheese, and that’s an “off” thing that freaks out most SE Asians (I love cheese, but can see their point: “What? That stuff is squirted out of a farm animal’s body, and if that isn’t bad enough, you let it go bad before you eat it!”).
If I haven’t been able to convince you, and you really, really can’t bring yourself to add the fish sauce, then I would go against the advice upthread to add soy as a substitute. Soy is very strongly flavoured and can overpower dishes it’s not designed for (most SE Asian curries, etc don’t use soy as it would seriously conflict with the delicate coconut notes). If you must susbstitute, then use plain ol’ table salt (maybe with a tiny amount of chicken stock), and hope that the other curry flavours will carry it off.
In all honesty, it’s one of those things where if I were cooking for you, I’d be tempted to lie to you and say I didn’t put the fish sauce in, and only tell you that I did when you’re smacking your lips after the second helping you’d asked for.
And if you still want to add soy - if you must - DO NOT add the Japanese stuff (Kikkoman etc). The cheaper “hydrolised vegetable protein” ones are milder and (marginally) better suited to your needs.
Don’t do that. If someone did something like that to me, I would never eat with them again until they had apologized profusely and sworn on whatever they believed in that they would never do anything of the sort again. If they didn’t apologize, I doubt I would be friends with them any more. And if they did apologize and never do it again, I still wouldn’t trust them as much as I had before they did that, at least not without many years of scrupulously honest behavior after the incident backing them up. I have the right to not eat whatever I don’t want to eat, for whatever reason.
Another thing to consider is that fish sauce changes in taste and intensity considerably once cooked. I am not fond of raw fish sauce but cant imagine most of my thai and cambodian dishes without it. I also make an amazing salad dressing with fish sauce, lime juice (LOTS) and chili sauce. The lime juice smoothes out the fish saice too.
Always cook your sauces. Fish, Oyster, Hoisin, all of them. And they all taste like all-get-out if you just have them by themselves. They are not ketchup.
My Asian food product choices are very limited here in Puerto Rico. This is Kikkoman country and nothing else. I used to like LaChoy at some point in life but then changed to Kikkoman and stopped trying around.
Kikkoman is brewed. This makes it heavy and complex in flavour. Great for what it’s designed for, but not so good for some SE Asian dishes.
Most of my… actually, no… EVERY SINGLE Vietnamese friend I have (and I have heaps because of where I live and work) uses Maggi “Seasoning”. That’s the one that comes in the squarish bottle with the red and yellow label. It doesn’t mention “soy” anywhere on the label because it’s not technically a soy sauce (it’s that hydrolised vegetable protein stuff) - but it is used in place of one. This stuff is great for all Vietnamese food that calls for soy. Failing that, find a Chinese grocery and just pick a brand at random (don’t go to a Japanese or Korean place though).
There was some sort of media beat-up health scare a few years ago regarding hydrolised vegetable protein. All my Vietnamese friends promptly switched to Kikkoman. They lasted about a week.
Off hand I can think of several Thai dishes where the fish sauce is not cooked. Som tum would be the principal example. Although I agree that fish sauce is a bit, um, pungent for eating straight up.
The Vietnamese will use it as an uncooked condiment sometimes, but they usually mix it up with a little water and whatever else takes their fancy. About the only time I’ll use undiluted, uncooked fish sauce is when I squirt a liberal dose of it into my pho - but that’s soup so it’s cheating a bit as fart as saying it’s ‘undiluted’.
