Vegan Fish Sauce Substitute

I encounter recipes all the time that call for fish sauce. But as a vegetarian, I don't eat fish. So I started looking around and reading what people do for vegetarian substitutes. A lot of people just replace it with salt. But that seems like the crudest possible approach -- even soy sauce would be a better approximation. So I read a bunch of sources and ended up liking this one best. The author has a sort of science-first philosophy without getting bogged down in rigorous trials. So I adopted that base-point and branched out a bit.

I started with these ingredients:

I put about a quarter package of the shiitake in the hot water, added a big stick of wakame, some salt and shoyu, and brought it to a boil, reduced the heat so it would simmer away, and let it be. It starts like this:

And ends up like this:

At this point, all you have to do is strain and let it cool.

It's just incredibly savory. I'm sure it doesn't perfectly replicate any real fish sauce, but it's got salt and umami and earthiness. It's way too strong to enjoy sipping as it is, but hopefully it'll be better in any recipes than just ignoring the fish sauce.

One amendment that I'm going to try next time I need to use some of this is to blend in some live miso. I worry that there's a bunch of subtle compounds generated in the fermentation process missing from this recipe, and maybe a strong, dark miso will help add some of that back in.