I read this book years ago, but all I remember is one scene from it. It's a hero’s journey style book I think. What I remember is the main character ended up going to this island where there was a beautiful woman who served them food, but it turns out it was actually an illusion and the food was rotten and she was ugly or old or something. She was a witch I think. Idk if this is enough to find anything but if anyone can it's driving me crazy trying to figure it out.
There's a scene that matches somewhat in A Spell for Chameleon (Xanth, book #1), by Piers Anthony.
In this book, the main character, Bink, finds himself on an island (disguised as a yacht) with an Enchantress named Iris, whose magical talent is illusions.
Iris returned, bearing a steaming platter. She had changed into a housewifely apron, and her crownlet was gone. She looked less regal and a good deal more female. She set things up on a low table, and they sat cross-legged on cushions, facing each other.
"What would you like?" she inquired.
Again Bink felt nervous. "What are you serving?"
"Whatever you like."
She made a moue. "If you must know, boiled rice. I have a hundred-pound bag of the stuff I have to use up before the rats catch on to the illusory cat I have guarding it and chew into it. I could make rat droppings taste like caviar, of course, but I'd rather not have to. But you can have anything you want—anything at all." She took a deep breath.
He turned, and for a moment looked back. There was Iris, standing in the splendor of her female fury. She was a middle-aged woman running slightly to fat, wearing a worn housecoat and sloppy hair net.
A Spell for Chameleon, chapter 4: "Illusion"
IDed by recognizing the scene and remembering that it matched.
There is a scene like this in Card's A Planet Called Treason.
The hero, Lanik Mueller, swims to the island of Anderson looking for answers as to who the villain is. He arrives and is almost drowned in the harsh surf, but is rescued by a beautiful woman.
She takes him to her pleasant cottage, with flowers growing around it; a nice homely place where she offers him a meal.
Fortunately something cues him that there is something amiss and he slips into quicktime, which breaks the illusion. The meal is nonexistent, the place is a hovel, and the ugly old man is about to kill him.
It was then that I saw her, a girl who couldn't have been older than twenty, dressed in a simple garment that didn't come to her knees. She was winsomely beautiful, and the light breeze tossed her black hair.
From a distance, when I had first seen her house, I hadn't noticed the flowers growing around the walls. They made a pleasant contrast in this land of desolation, and I found myself liking her. She offered me food, showing me a cold stew that she could soon heat up.
I pushed into quicktime. The knife was only a handspan away from my throat. The nude young girl was now a vile, ugly old man, with perhaps the most vicious, hate-filled expression I have ever seen on a human face. His eyes were deep-set and watery, his face gaunt with poverty. I had no doubt what he was after. His skeletal body cried out for meat. By comparison to him, I was fat.
The bed I was on was not soft, either—it was a board, and so hard and ungiving that when I slid awkwardly out from between his legs, he hardly bounced. I stood there for a moment, wondering what to do. The door to the kitchen was still open. I went in and found that the stewpot, far from being full of cold stew, was actually dusty from nonuse. None of the interior finishing that had made the place look homey and inviting was real—it had made way for rough sod walls, a dirt floor, and filth everywhere.
I don't actually remember if it took place on an island, but otherwise this reminds me of a scene from A Spell for Chameleon. The protagonist Bink meets Iris, the Queen of Xanth. She feeds and clothes him, but it's later revealed that she's just wearing rags and that she is the Sorceress of Illusion.