You should probably consider how embargo on oil have worked out. It is common for countries not embargoed to purchase oil for resale to embargoed countries, acting as middle men and attaining substantial profit on the transactionChina helped us in WWII to fight the Japanese. After the war they had a civil war… communist vs patriots. The Communist won and the patriots fled to Taiwan. The communist didn’t pursue and left them alone. It could be suicide for China to invade now, they gain nothing and stand to lose more than they know. But the leader has killed everyone that doesn’t think like he does. No one is telling him the truth or they die. So if he thinks it’s good to take Taiwan they all tell him it’s a good idea. All it takes is a good president to say we will no longer send food to China and in a couple years half their population will starve to death. We wouldn’t need to fire a shot. Nobody is telling XI that. Biden sure isn’t. China gains Taiwan but loses in the end. There’s just nobody left in China to tell XI that.
It is virtually certain that a food embargo against China would play out the same way, there is too much money to be made breaching the embargo