Sole is a wonderful fish, which stands out with the simplest preparation. This way its delicate flavour and texture is highlighted to the highest level.
 
A fish as delicate and delicious as sole is deserves the simplest treatment when you are cooking it. You want to keep everything as simple as possible. You don't want strong flavours over-powering the flavour of the fish . . .  and with fish this nice, the more simplistic your method of cooking the better.