A promising route towards nanodevice applications relies on the association of graphene and transition metal dichalcogenides with hexagonal boron nitride (). Due to its insulating nature, has emerged as a natural substrate and gate dielectric for graphene-based electronic devices. However, some fundamental properties of bulk remain obscure. For example, the band structure and the position of the Fermi level have not been experimentally resolved. Here, we report a direct observation of parabolic dispersions of crystals using high-resolution angle-resolved photoemission spectroscopy (ARPES). We find that exfoliation on epitaxial graphene enables overcoming the technical difficulties of using ARPES with insulating materials. We show trigonal warping of the intensity maps at constant energy. The valence-band maxima are located around the K points, 2.5 eV below the Fermi level, thus confirming the residual -type character of typical .