During my time working in Spain I have sampled quite a few paellas. I have heard that originally paella was a meal made up of leftovers. Basically you would add rice, herbs and whatever vegetables you had left from yesterday. So use this principle – choose a favourite vegetable, providing it fits in. be versatile. I've also heard, that the paellas that came from Valencia in Spain were the original ones (I guess this is subjective) and that they contained meat as opposed to seafood/shellfish which has become the norm today. Anyway, many of my friends have nearly turned down my invitation to eat paella, believing that it contained seafood. When they learn there is an alternative, they are very happily surprised and I don't know anyone who hasn't enjoyed it.