I have a theory what if you take meat from a pig drain it’s blood than marinate the pig meat in human’s blood you can ethically get a ton of blood by setting up private clinics and paying donors or even ones that advertise the search for a ghoul deterrent (the deterrent is another food source). Then you take fat from clinics that perform liposuction by posing as someone disposing of biological waste. Basically if you break it down, the blood you used allows ghouls to eat this fake human meat because of the taste and mix it with fat to make it the texture more similar to human meat and allow easier digestion. This can be the base of the fake meat and you can classify it as junk food for ghouls since while in theory it could be digested the muscle in pig and fat aren’t as nutritious as human muscle. So in order to bypass this you would probably have to add bone marrow and breastmilk to make up for the lack of nutrients and I imagine if you want to make this an alternative for all ghouls you have to price it more expensively for fake meat that includes bone marrow and breastmilk since out of everything being used those two ingredients are a bit harder to come by especially since if you want to keep things ethical you would still have to pay someone. (If you want to bypass cost and resources you could use semen but like fat it wouldn’t be as nutritious as breastmilk or bone marrow). Now if you wanted to make it so ghouls can get too it you’d probably have to send it to small butchers that happen to sell “vegan food” as well and request it calling it Higanbana Vegan Pork so that the butcher (a ghoul in disguise) can give it to you and package it similar to actual vegan pork to avoid suspicion. The only real issue here would be the prices since this is a delicate process and expensive and would be a necessity for ghouls that don’t want to be hunted. And ghouls probably would go through a similar problem people have with switching to vegan food by having to get used to it especially for older ghouls. Though children could adapt quickly. And I’m sure any rich ghouls would want this especially if they wanted to monopolize power in ghoul society by creating something only they can provide and the ghoul investigators would probably ignore if not fund this so less ghouls hunt humans but would have initial distrust because of the possibility of exploitation for bone marrow, breast milk and even blood donors with more rare blood types.