The radiation left over from the Big Bang is the same as that in your microwave oven but very much less powerful. It would heat your pizza only to minus 271.3*C - not much good for defrosting the pizza, let alone cooking it.
Stephen HawkingNot to take this web of dualities as a sign we are on the right track would be a bit like believing that God put fossils into the rocks in order to mislead Darwin about the evolution of life.
Stephen Hawking