  In a counter-ion only charged fluid, Coulomb coupling is quantified by a
single dimensionless parameter. Yet, the theoretical treatment of moderately to
strongly coupled charged fluids is a difficult task, central to the
understanding of a wealth of soft matter problems, including biological
systems. We show that the corresponding coupling regime can be remarkably well
described by a single particle treatment, which, at variance with previous
works, takes due account of inter-ionic interactions. To this end, the
prototypical problem of a planar charged dielectric interface is worked out.
Testing our predictions against Monte Carlo simulation data reveals an
excellent agreement.
