Studying the initial pre-hydrodynamic stages in heavy-ion collisions is an exciting research frontier, which becomes even more important for light-ion collisions. There, the system spends a larger time fraction before hydrodynamization, where the plasma is initially very far from equilibrium, and standard hydrodynamic methods are less reliable. This out-of-equilibrium plasma may affect and influence the propagation of hard partons and jets. To calculate the medium-induced gluon spectrum of such a parton and consequently jet energy loss, knowledge of the momentum broadening kernel is required, often used in a harmonic approximation using the jet quenching parameter $\hat q$. In this talk, I will present our results for the momentum-broadening kernel from QCD kinetic theory, which describes the probability of a jet parton receiving a momentum kick. In particular, the results for the broadening kernel are consistent with the previous extraction of the jet quenching parameter $\hat q$, and we find that at early times, small momentum exchange processes are more likely than expected from a Landau-matched thermal system, which is opposite at large momenta. Our results may lead to a better understanding of jet quenching during the initial stages, which can be particularly significant for light-ion collisions.