  Models of asymmetric dark matter (ADM) seek to explain the apparent
coincidence between the present-day mass densities of visible and dark matter,
$\Omega_{\mathrm{DM}} \simeq 5\Omega_{\mathrm{VM}}$. However, most ADM models
only relate the number densities of visible and dark matter without motivating
the similar particle masses. We expand upon a recent work that obtained a
natural mass relationship in a mirror matter ADM model with two Higgs doublets
in each sector, by looking to implement dark electroweak baryogenesis as the
means of asymmetry generation. We explore two aspects of the mechanism: the
nature of the dark electroweak phase transition, and the transfer of particle
asymmetries between the sectors by the use of portal interactions. We find that
both aspects can be implemented successfully for various regions of the
parameter space. We also analyse one portal interaction -- the neutron portal
-- in greater detail, in order to satisfy the observational constraints on dark
radiation.
