They eat some nice spaghetti, but it turns out to be dead people from another planet, and Morty is mortified. The planet learns about this and begins factory farming their own people for profit.

Morty tries to get around the moral anguish after learning the truth in different ways, just like carnists will try to eat meat and not cry about it: say it is consensual, they had a good life, maybe they can bioengineer alternatives, etc.

The solution was actually good IMO. In the vein of Impossible burger et. al. Rick says to kill just one more person and he can synthesize spaghetti without harming anyone more. But the killing machine also broadcasts the person's life as it flashes before his dying eyes, and everyone becomes disgusted by the concept of eating spaghetti as a whole and gives up on even the "harmless" alternatives.

That is my position on vegan meat and dairy engineered alternatives...we don't even need the category, and trying to keep it around only halters the fundamental goals of veganism. It seems to still be a controversial opinion among certain groups of vegans. So I was pleasantly surprised to see Rick and Morty of all places have a reasonable take.

The last scene has the family eating steak after giving up spaghetti, willfully ignoring their new moral doubts. Rick hints at the fact that it is just as bad if not worse, but everyone just laughs and continues eating. Kinda a typical Rick and Morty final scene, but also hits differently in this episode.

I recommend watching it! Just beware the TWs, it is an edgy show still...