  We introduce the generalization of the Slave-Spin Mean-Field method to
broken-symmetry phases. Through a variational approach we derive the
single-particle energy shift in the mean-field equations which generates the
appropriate self-consistent field responsible for the stabilization of the
broken symmetry. With this correction the different flavours of the slave-spin
mean-field are actually the same method and they give identical results to
Kotliar-Ruckenstein slave-bosons and to the Gutzwiller approximation. We apply
our formalism to the N\'eel antiferromagnetic state and study it in
multi-orbital models as a function of the number of orbitals and Hund's
coupling strength, providing phase diagrams in the interaction-doping plane. We
show that the doped antiferromagnet in proximity of half-filling is typically
unstable towards insulator-metal and magnetic-non magnetic phase separation.
Hund's coupling extends the range of this antiferromagnet, and favors its phase
separation.
