Well, not sure it is entirely willpower though.
I get cravings for particular foods when I have a deficiency. It's normal for me to crave foods like salmon, oysters, egg yolks, spices, liver, butter, etc. I think that's pretty cool that my body can make me crave certain foods, in order to make sure I get a certain nutrient.
So, if I force myself to eat only beef, I have to make sure I get a wide variety of nutrients. To calm down any potential cravings.
Today, I cooked beef heart. It was very dark red and bloody...just like liver. So, hopefully, that will help depress cravings.