The Dyllis Deluxe is the best HP recovery item in Super Paper Mario. It recovers 90 HP and cures poison.
It is made by combining a Shroom Steak and a Gorgeous Steak or a Roast Shroom Dish with Dyllis in Flopside.
In order to get a Shroom Steak, simply cook an Ultra Shroom Shake. To get a Gorgeous Steak, you must get two Power Steaks, cook one into a Hamburger with Saffron in Flipside, and combine both the Power Steak and the Hamburger with Dyllis.