If you don't like olives just omit them, but I feel that olives give an added dimension to the flavour. Dried fruits are used a lot in Moroccan/North African tagines, such as apricots, dates or prunes but I only had dried apple so didn't bother. Also used a lot is preserved lemon but again, I didn't have any. Rose petals are used in a lot of dishes, most harissa pastes contain them, as does a lot of the ras al hanout powder. You can buy bottles of rose water and just add a splash of that. All of these different ingredients enhance what is basically a stew/casserole and gives it it's authentici