We suggest that charged current production of mesons in Bjorken kinematics allows a very clean extraction of GPDs, and demonstrate that simultaneous study of parity conjugate mesons (e.g. $\rho$-mesons and pions) provides very sensitive probes of the \emph{difference} of meson distribution amplitudes. We expect that such processes might be studied in the future in neutrino-induced and electron-induced processes.