  We propose a method for calculating the Franz-Parisi potential for spin glass
models on sparse random graphs using the replica method under the replica
symmetric ansatz. The resulting self-consistent equations have the solution
with the characteristic structure of multi-body overlaps, and the
self-consistent equations under this solution are equivalent to the one-step
replica symmetry breaking (1RSB) cavity equation with Parisi parameter $x=1$.
This method is useful for the evaluation of transition temperatures of the
$p$-spin model on regular random graphs under a uniform magnetic field.
