In this paper, we propose a content-based, advanced level adjunct English as a Second Language (ESL) instructional approach for writing from a language socialization theoretical framework using basic principles of systemic functional linguistics (Halliday, 1994) and sociocultural theory of learning (Vygotsky, 1986). We emphasize an ESL curriculum that stimulates ESL students to learn domain specific knowledge, to develop cognitive and meta-cognitive learning and thinking processes, and to learn rhetorically and lexico-pragmatically appropriate writing (Raimes, 1983). We provide a complete review of the theoretical principles derived from research based on integrative curriculum for second language (L2) students. We explain how an adjunct course model (Adamson, 1993; Mohan, 1986) can be used to design the specifics of the course.