ok, We have great Aji info and links, we have a few recipes that seem close, and it seems this recipe may be a family/business secret (sauce :O)
I'll soon start trying variations of the hints given so far. I don't have immediate access to real "Aji" peppers - so I'll substitute a mild Jalepeno (stemmed and seeded). I will share my results - you will all appreciate this stuff!!!

Don't get me wrong, I like heat! I have two Habenaros on my pourch (one red, one orange - both scortching hot), but this sauce has very little heat in it. It's almost like they used a few green bell peppers, and maybe a young green Aji chillie or two in each big batch they must make. It's creamy, but not so smooth that it's runny... it must be blended fairly fine at some point in the process.

This sauce is served in 10-12 oz squeeze bottles and I have noticed that everyone in this tiny little restaurant uses this stuff on the bread served after ordering, and all over just about every dish they make. The bottles are replaced (because they are empty) after each table finishes up and leaves.

Karen mentions a simple recipe with "Crema Mexicana" and my guess is that there is something like this (if not this specifically) in this joy juice. I would be amazed if it didn't have some avocado in it, and my friend that took me there the first time told me the owner suggested there was lettuce in the mix. I can't picture the lettuce - but maybe it adds to the thin but thick (I know this doesn't make sense - it's difficult to explain... every time I think of this stuff I start drooling :O) texture.

It tastes exotic somehow. You can pile it on the Peruvian bread real thick - so thick that it starts running off the sides... (everyone does it) and it's not hot to me at all. Others I've taken to Pollo Inka have said the sauce was pretty spicey - I eat peppers everyday, so my tongue may be a bit used up...

It's super on rice, and all the meat dishes I've tried it on taste wonderful. I make Carne Asada Tortas on my BBQ quite often, and If I have any of this sauce in the refrig - both sides of the Mexican bread get completely smothered with this stuff after toasting. It never last long - and I get 2 ~40-50 oz containers ($20/ea) of the stuff everytime I go on my pilgrimage. It's great on toast! (but so is avocado w/salt& pepper).

Now I'm pretty sure there are those who know about this secret sauce out there. It probably comes in a million small variations... PLEASE, please share your wisdom with us. I would never injure Pollo Inka by not frequenting their facility... There food is too good (and the sauce is out of this world) !!!

Wait until you try this stuff folks. It is to die for. :O)