While this is not "bilingual approach to teaching English" it is a strategy for incorporating the learners' first and additional languages in the classroom. In teaching writing in an additional language, it is often useful to utilize the students' writing knowledge and experience from their first language. Making the student aware of their prior knowledge in writing a specific genre in their first language, could help them to acquire that genre in the additional language. If the students ignored their first language writing, this may limit any potential transfer knowledge, or even of general writing strategies. As well, this disconnection could lead the students to perceive themselves as inexperienced writers instead of learners with years of writing experience in their first languages.
Another topic that may interest you is "Translanguaging". These articles may be of interest;
Bauer, E. B., Presiado, V., & Colomer, S. (2017). Writing through partnership: Fostering translanguaging in children who are emergent bilinguals. Journal of Literacy Research, 49(1), 10-37. 10.1177/1086296X16683417
Creese, A., & Blackledge, A. (2010). Translanguaging in the bilingual classroom: A pedagogy for learning and teaching? The Modern Language Journal, 94(1), 103-115. 10.1111/j.1540-4781.2009.00986.x