The day before he left Captain Strange decided to buy a couple of pizzas for dinner. This is when I discovered (through inference - in the same way people discovered atoms) that there are gnomes that live in the fridge. Fridge Gnomes (as opposed to Garden Gnomes who hate puppies and want rainbows to die) are master culinarians and have magical powers to transform food.
There is an obvious hierarchy of foods that Fridge Gnomes like to work with. Pizza and Chinese food (the worse it is for you the more they like to magic it up) are on top of the pyramid, while pasta, fresh salads, and cooked spinach are on the squishy, rotten bottom.
This is how I imagine Pizza is transformed by the Fridge Gnome's magic:
The Gnome assesses the Pizza and must decide that it is a high enough quality pie to qualify for his magic.
The Gnome then blasts the pizza with his blue power ray of awesome.
At this point awesome left overs are created after the Gnome has used his holy powers to cleanse the pizza of all evil.
