Smart learning environments offer rich opportunities for language learners. In particular, context-aware systems which allow learners' progress to be sensed within and across an activity, enable instructed language learning to move beyond the traditional confines of the classroom walls. In this paper we present the European Kitchen, a real-world task-based environment for cooking and language learning. In doing so, we demonstrate how specific design decisions, in the development of this longer-term iterative design project, conjoin Human Computer Interaction practice and learning theory for situated language learning. We also show how this approach is combined with Conversation Analysis, which is used as a tool to measure the impact of these decisions on the interactions taking place in and with the kitchen. Our work reveals that in order to design for and evaluate effective and meaningful language learning, there should be more balance between technologically-driven theory and theory driven research which has a strong pedagogical foundation. Our work has implications for a transferable, interdisciplinary model of task-based, situated learning which can be applied and adapted to different skill and knowledge sets.