  We point out that a distinctive mono-top signature is present in Natural SUSY
scenarios when a scalar top-quark and higgsinos are almost mass degenerate.
This signature originates from a supersymmetric counter part of the $t \bar t
H$ process, i.e. $pp \to \tilde t t \tilde h$. Unlike mono-jet signatures
exploiting initial state radiation, this channel can be regarded as a smoking
gun signature of a light stop and higgsinos, allowing a direct probe of the
stop and neutralino sectors. The production rate of this channel largely
depends on the up-type higgsino components in the neutralinos while the stop
sector is sensitive to angular distributions of top-quark's decay products. We
develop an optimal search strategy to capture the supersymmetric $t \bar t H$
process and find that a high luminosity LHC can probe the stop and higgsino
sectors with $m_{\tilde t_1} \lesssim 380$ GeV and $m_{\tilde t_1} - m_{\tilde
\chi_1^0} \lesssim m_W$. Additionally, we propose a kinematic variable with
which one can measure the stop mixing in this channel.
