Grounded Theory (GT), a sociological research method designed to study social phenomena, is increasingly being applied to investigate human-centric and social aspects of software engineering. Despite its strong potential, GT remains a largely misunderstood, misused, and poorly presented and evaluated method in software engineering. Inevitably, software engineering researchers attempt to adapt traditional GT to suit their unique socio-technical contexts but without philosophical rationales or methodological justification. At the heart of these challenges lies the misalignment of GT's traditional social sciences approach to studying what is an inherently and inextricably socio-technical discipline and the absence of clear methodological guidelines to bridge the gap. Motivated by the needs of the software engineering research community and an acknowledgement of the misalignment of the traditional GT methods to studying an increasingly socio-technical world, this paper outlines the Socio-Technical Grounded Theory (STGT) method, a variant of the traditional GT methods. With its unique socio-technical lens, STGT presents philosophical and methodological guidance for studying socio-technical phenomena and theory development in software engineering and related disciplines.