  We propose an alternative experimental protocol for the detection of doped
Chern insulators and chiral superconductors. Our approach relies on coupling
the target chiral system to adatom spins. Due to the substrate chirality, the
adatom spins are expected to order in a noncoplanar configuration with a
nonzero spin chirality. Here, we obtain concrete results for chiral substrates
which are invariant under arbitrary spin rotations, and are coupled to three
adatoms carrying classical moments. By exploring all the accessible magnetic
ground states, we identify the regimes in which nonzero spin chirality is
induced on the adatom complex. We apply our method to valley-polarized bilayer
graphene and $d+id$ superconductors, and find qualitatively different ground
state diagrams. Our analysis shows that the adatom spin chirality fully encodes
the properties of the substrate chirality.
