Ed-0: Zombie Uprising

First, you'll need to find a regular 'rice ball'. The quickest way is to enter a yellow 'food' gate for the floor transition. Then, find a way to cook it. If you went into the food gate, there most likely are 2 torches flanking the exit gate. Hit or to cycle through your items while in-game (not menus) until you have the rice ball selected. Then, hold to go into aim mode and then to throw the rice ball at the fire. It should fall to the ground as a 'grilled rice ball' - achievement unlocked.

Any fire source will work, including the flaming zombies, flame armor talisman, or even the ninja's flame jutsu.