Mistake
A Mistake is an item found in the Paper Mario series. The item is created when Mario mixes incompatible ingredients. A Mistake heals a measly 1 HP and 1 FP. Of course, the goal of cooking is not to make something like this. In Paper Mario: The Thousand-Year Door and Super Paper Mario, the Mistake counts towards finding all 57/96 recipes.
There are literally hundreds of combinations to receive a Mistake so make sure you know what you're cooking. However, a Mistake is actually slightly superior to a Dried Shroom, since it restores 1 HP and 1 FP, compared to the Dried Shroom, which only restores 1 HP. If you cook a Dried Shroom before returning Maitre Delish's Cookbook, you will get a Mistake. If, however, you cook a Dried Shroom AFTER returning the Cookbook, you will get a Shroom Fry instead! Mistakes sell for three coins in Twilight Town, but one coin everywhere else.
In Super Paper Mario there are two types of Mistakes-and one of them is actually useful. By having Saffron cook a Sleepy Sheep she will make another kind of Mistake that puts multiple enemies to sleep.