Throughout history, leaders have been worried, often justifiably, about the possibility of poisoning, which probably accounts for the prevalance of food tasters. Some of them have taken this suspicion to extremes. According to this (perhaps not well-sourced) article, queens, kings, popes and emperors have gone to extraordinary lengths to protect themselves from poison, from using special cutlery to rituals and supposed universal antidotes. Of course, the practice of using food tasters itself is another example of this abundance of caution.
Since most poisoning attempts have historically involved poisons added to food after or during preparation— it is, after all, far easier to poison a soup than a tomato—it would seem logical that some leaders' paranoia might have led them to try to eliminate the possibility of betrayal in this area altogether. However, some searches didn't turn up any examples. Are there any historically attested examples of leaders who insisted on preparing their own food so as to avoid poisoning attempts?