Abdo, The use of "has had" in this sentance indicates the present perfect tense, which describes an event from the past that has some connection to the present. The ongoing events here are the cooking experiments.

I understand that it is confusing, but it is really just using the verb "to have" in the same manner that other verbs are used in the present perfect tense. The present perfect talks about events that happened in the past, but relates them to the present: for example: "I have studied today" (up to now, I have already studied on this day). "Had" is just the past participle of "to have" So, "has had to endure" means, in the past, but up to now, someone has endured (had to suffer) the other person's cooking. I hope this helps. A proper grammar teacher may be able to give a better response.