Paul - You know, thinking about it, we're as bad as each other, i.e. in potentially misleading anyone else who might decide to try that recipe. When you first recommended it, you mentioned that you co0ok the onions a different way but you didn't say anything about changing the spice mix to mix powder. This could make a big difference, which you only revealed later.
I didn't do that but I did reduce the lamb, onions, ginger and garlic by 50% whilst keeping the spice quantities the same (effectively for double strength). This could also make a big difference.