I have lived in Valencia for many years. True paella never contains onions cooked sprinkled over or any other fashion. Garlic yes. To cook Paella Valenciana correctly you need rabbit & chicken jointed into bite sized pieces, Fry the chicken & rabbit in decent cooking grade OLIVE OIL until browned, adding plenty of garlic, bay leaf, sprig of rosemary such that that browns slightly too, all together. At that stage you need to add the paella rice ( the ROUND rice) & stir it in for a minute or two before adding tomatoes, chicken stock, slices of green pepper, butter beans, runner beans, paella powder ( essential), paprika, and a few strands of saffron ( essential). Note the ratio of liquid to rice is TWO TO ONE! After a lot of anguish I learned that from a lady running a small cafe in Valancia. Season with salt & pepper. Let this lot stew away on a low heat for say 20 to 25 minutes until the rice has absorbed the liquid. It should be caked, NEVER STIR IT, let it get crusty & slightLy burned on the bottom ( BUT not cremated) for a delicious nutty flavour.THEN, TURN OFF THE HEAT, COVER WITH A LID OR TINFOIL & let it stand for about 5 minutes. The rice will rise and become fluffy. Your paella is ready!