Well now we're getting somewhere.  This is the closest I've come yet and I have to say it is not terribly unlike other versions I've eaten, but still not exactly what I'm after.  I can't thank CT enough as I now have the knowledge I needed to get experimenting and I'm definitely on the right track.

My fussy daughter is the judge and she says it is still "too much like a curry" and not yet rich enough.  So the first thing I'll do is pre-cook the chicken in a milder base gravy, (although I don't think that's the problem), using less mix powder and possibly even none.  After that when I'm actually assembling the dish, I'll again use less base and more mango and possibly more almond meal as well to thicken it a bit more.

The dishes out here, at least the one I'm trying to replicate, are very sweet mango, but with a richness and velvet creaminess with only a hint of spice.

I'm still open to suggestions, but this is the best result so far in over 10 years of trying.

Now to make a Rogan Josh to go with it for my own dinner.

I'll let you know how the next few variations work out and hopefully I'll get that "Eureka" moment.

OK. So that is understandable but still a little disappointing.  The slight variations from shop to shop would be from the variation to individual butter chicken sauce. 

Which is your butter chicken gravy mentioned above?  Could you provide a link to it?

edit: don't worry . Found it

Could use help with the Cashew Gravy though.

I still think it will still be requiring cream or curd or something, maybe coconut cream, or a mixture of these.  Maybe not. I can see I still have some experimentation to do.  I have been down the path of Butter Chicken / Mango Pulp before and as I say it is nice to eat and similar but not the same.  I've also experimented with cashews before.

This is the thing. It tastes like Mango Chicken.  It is not a korma but it is mild.  It is sweet but not sickly. It is mild but complex.  It does not have definite flavours of coconut, or heat of chili.

It tastes like Mango Chicken.  I can't even say for sure if it contains a base gravy or any onions for that matter.  I simply do not know how to describe it other than delicious and the kids love it.  It is like chicken for desert.

Hi Livo

We do mango chicken and it's a good seller.

We add 1/3 portion of korma sauce, 1/3 portion of butter chicken sauce(our recipe is on here), 1/3 base gravy and add a good 5 tbsps of mango pulp. Add chicken, heat through thoroughly and that's it.

May be a bit of faffing about to make up korma and butter chicken, but you can freeze the remainder for further recipes.

You could probably get away with just korma/base 50/50, plus the mango pulp. 

I

Hey Mick,
What chicken do you use?  Plain raw, pre-cooked (boiled in spice / flavouring), Tandoor or Tikka?

The dish is usually a very orange colour (probably food colouring as the mango pulp doesn't hold up in colour with the other sauces).  I found one reference in a restaurant menu to the use of Deghi murch, which I found is Kashmiri Chilli powder (deggi mirch), used for colour, but I imagine this would also provide heat and the dish is never hot. I have only seen it as "Mild" and on one menu listing as "Medium".

Thank you both, Rob and Mick. 

@Rob:- I'd already looked at the link you provided. I found it yesterday but the dish I'm looking at is usually a very creamy, velvety gravy / sauce and listed as mild.

@Mick:- I can buy it anywhere in 5 places within 30 minutes (1 hour return) from home with the closest place 15km away as I live in a rural area.  They are always a little bit different (as you'd expect) from shop to shop, but the basic concept is pretty uniform. I'm from the Central Coast of NSW and I can get it at the main Curry houses around Gosford area. I'm presently living around Lake Macquarie, and can get it close to home or in Newcastle. I've had it in Sydney and in Tamworth.

I've been able to come close but just never quite get it.  I do know that it uses canned puree of Alphonso Mango as I once caught a glimpse of the cook starting a new batch after I bought the last of it.  I have made blends of Butter Chicken with Mango, Korma with Mango, just Mango with yogurt, cream and coconut and mixtures of the above. I've tried small amounts of powders etc but just cannot get the dish right.

It is very frustrating that it is so commonly available but is shrouded in mystery.  I was a school teacher and had a student who's father was the cook at one of the stores. They would not tell me and just grinned at me when I asked.