Is Landau free energy really the free energy

I recall reading in Negele&Orland’s book that Landau free energy function is not really the free energy that one obtains from the partition function $$F = -frac{1}{beta}log Z.$$ Indeed, the real free energy is already averaged over all possible states and its expansion will never produce a nice shape with multiple minima, used in Landau’s analysis of phase transitions.

Question
Is Landau energy just a useful theoretical conjecture or is there a principled way of constructing it from a partition function? Examples will be appreciated.