Superman's heat vision is a cool tool that allows him to project rays of energy (IR, X-Ray,or whatever the writers come up with) over an undefined range. He has used it for many great (and not so great) feats, including melting glaciers, shaving and leaving writings on walls.
There is one more use one can think of for such a versatile power: cooking! Has Superman ever used his heat vision to cook (not his enemies!) food?