That’s what was used in the 1975 movie Mandigo, and, perhaps as a practical matter, the basin wasn’t a big globular cauldron but more like a giant iron contact lens.
In the Cornel Wilde movie The Naked Prey, the spit-roasting method was employed, but the victim was first covered in clay to seal in the juices. (Dad thought it would “toughen us up” to let us stay up and watch that movie. Such nightmare fuel!)
Clay pots are sealed and baked in ovens until the meat is falling off the bones.
Basically Scarlet Pimpernel, Zorro, then The Shadow, and even Doc Savage but since none of these characters had actual super powers can they be considered “Superheroes”. Hercules and simular characters were definitely superpowered but didn’t have a secret identity.
Actually now that I think about it does Popeye count either? After all we never see the story of mild mannered Peter Poopdeck.
One of the color Popeye cartoons from the '50s has Popeye force-feeding spinach to Bluto, who goes into some sort of uncontrollable rage where he just starts throwing punches randomly.
I think there were two instances in the original black & white cartoons where someone besides Popeye ate spinach. In “Never Kick a Woman,” Popeye takes Olive to a gym to learn self-defense, but the teacher is a female bombshell who has eyes for Popeye, until Olive eats some spinach and beats her senseless. In “Lost and Foundry,” Popeye and Olive are working at a foundry, and take Swee’pea with them for some reason; Popeye and Olive get their feet stuck in a machine that’s about to press them flat, and just as Popeye is about to eat his spinach, the machine knocks it out of his hand, right in front of Swee’pea, who eats it and manages to crawl under the press and lift it out of the way. They might be online (say, on YouTube).
Tell me about it. My folks went to see it at a drive-in, and took nine-year-old me with them. It was not a movie for a little kid to see, and I was sickened to the extent that I threw up my popcorn and soda out onto the asphalt. In his defense, my dad thought the movie was going to be about wild animal hunting in Africa.
The thought of it still squicks me out, fifty-seven years later.
It sint? 
I hate cooked spinach. Raw in a salad is fine.
The current big winner on jeopardy is getting flack for being slow.
Canning is a horrible thing to do to spinach. Even in the few dishes where it’s (barely) acceptable, fresh is still far, far better.
You mean, like Batman?
Yeah, when I say I “like” canned spinach it’s only in other dishes and when nothing else is available. If I have a choice, I’ll take either fresh or frozen.
Apparently, they were a real thing. In castles, that is, not for cannibal tribes.
See the sequel cartoon Another Froggy Evening.
here ya go they have different varieties:
Written and produced by Chuck Jones himself, so I guess that’s as canonical as it gets.
ETA: I’m always impressed by how cavemen were brawny enough to handle giant slabs of rock.
perhaps he’d been eating spinach.
Interestingly, the portrayal of Zorro by Fairbanks back in 1920 involved having one we heck of an in-story mystery-man reputation (“This Zorro comes upon you like a graveyard ghost and like a ghost he disappears”), to the point where they start saying that “Zorro knows the deeds you do before you think them — takes any shape he wills — appears through keyholes!”
Sure, they’re wrong; they’re even, if you like, a cowardly and superstitious lot. But the fictional superhero they’re describing in the fiction is who Don Diego is passing himself off as when he puts on the mask and battles injustice; and, at some point, that’d count, right?
The Shadow had the power to cloud men’s minds.
I trace my love of superheroes to some of my earliest memories: late nights at my grandma’s cabin, listening to a huge old radio.
And I was captivated by those old radio dramas:
The Mask of Zorro, followed by The Lone Ranger, The Green Hornet… and then, Who knows what evil lurrrks in the hearts of men?
The Shadow knows…
Spoken by someone who’s probably never eaten a proper spanakopita.
I can see the script now. “Who knows what evil lurks in the hearts of men? The Shadow knows! LOL!”
…the power to what? 
Shouldn’t it be The Cloud that shadows men’s minds?
Is that something that is work safe??