Teaching a class of mixed EFL/ESL levels can be problematic for both instructors and students. The disparate levels of ability often mean that some students are not challenged enough while others struggle to keep pace. Drawing on experience in the university classroom in Japan, this practice promotes good preparation, self-reliance, inclusiveness, and maximum class participation. In two parts, this paper demonstrates how independent learning can be used to bring out the best in classes of this sort. The first part of the paper explains the method students use to create a self-learning portfolio. It will explain how students construct their portfolios to formulate questions and reach tentative conclusions before they arrive in class. The second part highlights the benefits of this system, presenting evidence that this approach engages students in mixed-level classes by fostering communication and inclusiveness. Examples are presented on how this mechanism boosts participation and motivation among even the most reluctant students. While bolstering engagement, this process at the same time offers opportunities for group consensus and strong student leaders to emerge. Finally, this paper concludes with a reinforcement of the merits of this system and how this effective technique creates a student-centered class.