Education systems around the world closed schools to cope with the spread of the COVID-19 pandemic. In this current mixed-method study, 181 schoolteachers completed online questionnaires to characterize the pedagogical strategies which they used during Emergency Remote Learning Environment (ERLE) in May 2020. In addition, we conducted semi-structured interviews with eleven ICT coordinators to explore their role in effective ERLE. According to the teachers, the most prevalent strategies that they employed were "synchronous strategies" (M = 3.75) and "blended" (synchronous & asynchronous) strategies (M = 3.64) categories, both found to be significantly higher than the asynchronous strategies (M = 3.30). Moreover, when teachers were specifically asked about their preferred medium, 52% of the pedagogical strategies were performed in "blended environments" combining synchronous and asynchronous communication channels, with only 22% of teachers choosing to teach synchronous lessons. Among the strategies, assigning students to design learning artifacts was the most powerful predictor ([beta] = 0.58) of designing authentic activities by teachers. Triangulation with the qualitative data of ICT coordinators showed that teachers utilized seven ERLE strategies differentiated by delivery medium naturalness: "asynchronous activity strategies" (68% of the statements) or "synchronous session strategies" (32% of the statements). Regarding the role of teachers as designers, almost 90% of the teachers designed and/or adapted the ERLE activities by themselves. The role of coordinators during ERLE was primarily to provide organizational, technical, pedagogical, and emotional support to the school staff rather than to develop learning materials. Teachers used both synchronous and asynchronous channels according to needs, to provided emotional and pedagogical support and to maintain authentic teaching and learning with their students. The implications for educational theory and practice are discussed.