As people above me mentioned, it is probably hard to find. Chile tends to have a bit better infrastructure for trekking than Brazil, but it is not Europe/US.
Looking online, I found this: http://www.lacumbreonline.cl/equipo-de-montana/cocina/nutricion/wise-comia-liofilizada-con-carne.html They have shops in Santiago, Puerto Natales and Punta Arenas, pretty much your main hubs if you plan on trekking in Chile.
That is pretty much what you're looking for, right?
The problem is that if I look at the website for my local (Brazil) mountain equipment store, they also have some options on their website, but the physical store does not carry it (here, but it's a chain, so maybe in some of the other stores they do have it). What I tend to do is just make up my own menu. You can get various different instant pasta meals, flavoured rice, mashed potatoes and soups at the supermarket. I then add in some fresh onions and carrots for the first 2 or 3 days, and maybe some canned fish, spam, corned beef, etc. Dried fruit is also easy to find here (presumably also in Chile, but not sure).
My main problem here is a bread replacement. In Europe I could find some pretty good hardtack that worked great, but I have not found anything similar here anywhere.