What looks like food, tastes like food, smells like food, sounds like food when you cook it, is grown in dirt like food, fills up your stomach like food, but is not food?
A poisonous mushroom. Since some types of mushrooms are edible, it can be very hard to distinguish between a safe mushroom and one that will kill you. Food is defined as a substance consumed to provide nutrition, therefore a poisonous mushroom that kills you doesn’t qualify as food, even though it shares all of the traits of a regular mushroom.
Other valid answers include anything that’s edible, resembles food, but is poisonous.
The moon. It has two sides, but on earth we only ever see one side. Man has been on the moon, but no one is there now. A full lunar eclipse is known as a blood moon, and the phrase “once in a blue moon” refers to something that rarely happens. Promising the moon is making an extravagant or impossible promise, and there’s a new moon once every lunar cycle.
A deck of cards. You put the cards on the table to play, and you cut the cards to mix them up, but you don’t eat them. Flowers is another possible answer.