Yes i was confused about the mushrooms as it says chicken dupiaza in the title. But you know what? i love mushrooms and being very savoury they should work really well in BIR!
I've never had a really good mushroom curry as here and in india they didnt cook them properly which was disappointing. They just cooked them with the sauce so they were that raw flavour rather than carazelized and savoury.
Right, you've got me hungry, i'm going to turn tonight's side dish of okra into a mushroom and okra special.

As for your CTM you could try using kashmiri chilli powder (or MDH deggi mirch) as that adds colour without much heat.

Cheers chinois will try some of that and will get back to you.
Thanks.