I would suggest the local takeaway and ask for a chicken Biriani. It is the very mildest dish I know. Consisting of chicken in rice with some very mild spices and a vegetable curry, also very very mild. The rice often contains sliced peppers, hard boiled egg, sultanas, tomato or other veg.
It is quite cheap as you don't need to order extra rice with it and will be about £6.00 for the entire dish. Once you have established if he likes it, then there are many recipes online.
If you do end up making your own curry remember that not only chilli adds heat. A high amount of ginger can also heat up a currys spice and make it unpalateable for beginners.
http://www.indobase.com/recipes/details/chicken-biryani.php
Above is one recipe for chicken Biriani. I would change one thing in it. If you boil the rice in chicken stock instead of water it adds so much flavour.
Whatever you do, I hope it turns out well.
Try a poppadum and a portion of onion bhajis with it is lovely. I started on this dish and now eat up to Madras strength, but still revisit it from time to time. I used to dislike curries and the owner of the very first restaurant that I went to recommended this as a start off dish.
I would still pale at the hottest dish on the menu even after 25+ years of curry eating.