This empirical study is conducted in a blended learning setting of a technology-focused private university in Bangladesh to offer a model that could help attain a comprehensive goal of blended learning. The main objectives of this study are to examine course design in a blended learning setting, strategies adopted by the course teachers to maximize students' online interactions in a collaborative manner and how well these strategies had an impact on quality of blended teaching and learning in tertiary education. Drawing upon a quasi-experimental approach, qualitative data were collected by observing the teaching and learning activities of a course named 'Bangladesh Studies' over a four-month semester. Findings of this study suggest a model that would allow better student--teacher interaction in both synchronous and asynchronous modes of teaching and learning based on three sequential stages such as referring to and discussing online peer-group comments in the regular face-to-face classes in asynchronous mode (stage 1), off-campus synchronous mode of interactions to utilize students' personal study hours (stage 2) and off-campus asynchronous mode of interactions to offer flexibility for collaborative learning (stage 3). It is argued that the model that has been offered could be useful in promoting innovative and contextual pedagogy which will essentially involve students in sharing, interacting and collaborating discussions for knowledge construction and hereby enable overall cognitive development of students in a blended learning environment.