Mommies, please advise on a good food oil (sunflower/olive/butter and …

Mommies, please advise on a good food oil (sunflower/olive/butter and so on) that can be given with weaning, and then added to meals, cooked for children. Do you use any specific one? Or do you take any at random? I'll say right away that in national program schemes and regulations it was written that oils can be added to weaning.