Thanks Lani for your comment, I really appreciate it - you are my first!!
I am really glad that you enjoyed the meal!!
You should be able to get lemon myrtle from the supermarket, although it is hard to find, it's not usually with the other spices. It is usually in a container with a black lid away from the others (I'm not sure why). It is an Australian bush spice that tastes a lot like lemongrass.
Definitely add chilli - I don't really like chilli as I find it too overpowering, but anyone who loves it should add as much as they like.