Cosmological first-order phase transitions may have played a significant role in the formation of baryon asymmetry and dark matter, potentially leaving an observable gravitational wave signature. In this talk, I will focus on the possibility of primordial black hole (PBH) formation from slow and strongly supercooled transitions. I will describe how the stochastic nature of the bubble nucleation process generates large inhomogeneities that can collapse into PBHs after the transition. Additionally, I will introduce a model where such transitions can happen and discuss the characteristics of the resulting gravitational wave background, which is sourced not only by the bubbles but also by the inhomogeneities.