Fried onions are a definite must!
I think I'll go back and try Biryani again, I cook on induction and I just need to sort out the timings. Thanks Dalpuri for the comments, I now remember that I should try putting a frying pan under the saucepan.
Cooking the meat seperately works fine but I'd like to master the one-pot style.
Apparently a good chef can tell when it's ready by hitting the outside of the pot and listening to the sound it makes.
*If anyone's interested in trying it there's a very good 'sour berry pulao' recipe in Rick Stein's India book, which while not a biryani is a very dish cooking the meat first.