  What is the most effective way to grill food? Timing is everything, since
only one surface is exposed to heat at a given time. Should we flip only once,
or many times? We present a simple model of cooking by flipping, and some
interesting observations emerge. The rate of cooking depends on the spectrum of
a linear operator, and on the fixed point of a map. If the system has symmetric
thermal properties, the rate of cooking becomes independent of the sequence of
flips, as long as the last point to be cooked is the midpoint. After numerical
optimization, the flipping intervals become roughly equal in duration as their
number is increased, though the final interval is significantly longer. We find
that the optimal improvement in cooking time, given an arbitrary number of
flips, is about 29% over a single flip. This toy problem has some
characteristics reminiscent of turbulent thermal convection, such as a uniform
average interior temperature with boundary layers.
