Actress Catherine Zeta-Jones has a simmering secret - she is useless in the kitchen.The Traffic star, married to Hollywood legend Michael Douglas, confesses she can't cook even a simple meal without the aid of a microwave.And she is so bad at baking that she once nearly set her kitchen on fire.The actress tells Sky Movies magazine, "I'm a terrible cook. I can microwave chicken nuggets well."This is a true story: I actually burnt a pan once. There wasn't a fire but it was smoking and I got a little scared. So that was the first and last time I tried to cook."