I also use Pataks and I cheat with the onions. I say I cheat but actually I use Eazy Fried Onions. They've been braised for hours and are sweet and when I use the Patak's Korma paste I zap a can onion, a can of coconut milk, some sugar, some dessicated coconut, ground almond and some yoghurt. I use some fresh garlic and fresh ginger to give it that authentic lift, then the paste goes in and then my mix. If it's lamb - then it then cooks slowly for an hour or two. It gives perfectly acceptable results.

I've become so reliant on the canned onion - which is as good as patiently braising - I keep a very large stock because it's exactly the sort of thing that gets dropped just as you start to rely on it.