The origin of neutrino masses remains a pressing open question. Among the possible explanations, the simplest involve Seesaw models, where the smallness of the mass of the neutrinos originates from the size of the Majorana mass of new sterile neutrinos. Its dynamic origin via spontaneous symmetry breaking would leave at low energy a remnant, a (Pseudo-)Goldstone boson, the Majoron. Generically, the Majoron remains massless and in phenomenology its mass is added ad hoc as a free parameter, remaining agnostic about its UV origin. In this seminar, the expansive landscape of potential UV models is streamlined by imposing minimality criteria, exploring the intriguing correlation between neutrino and Majoron masses. Remarkably, we find a unique model that satisfies all minimality requirements. We present its construction, its main characteristics and its phenomenology, paying attention to the delicate role of global symmetries(s) in its realisation.