  We report on a novel ab initio approach for nuclear few- and many-body
systems with strangeness. Recently, we developed a relevant no-core shell model
technique which we successfully applied in first calculations of lightest
$\Lambda$ hypernuclei. The use of a translationally invariant finite harmonic
oscillator basis allows us to employ large model spaces, compared to
traditional shell model calculations, and use realistic nucleon-nucleon and
nucleon-hyperon interactions (such as those derived from EFT). We discuss
formal aspects of the methodology, show first demonstrative results for
${}_{\Lambda}^3$H, ${}_{\Lambda}^4$H and ${}^4_\Lambda$He, and give outlook.
