This article examines contemporary expressions of human to more-than-human interaction through the lens of technoenvironments, understood as evolving networks that bind non-animate and animate life together, shaped by mutual agency, care, and resistance. We relate technoenvironments both to multinatural cosmologies recounting mythical origins of human society in Southeast Asia through the union of mountains and the sea, and to modern approaches derived from contemporary feminist political ecology. We explore performative practices which express and shape understandings of the co-becoming of humans and more-than-humans at case studies in Indonesia and Vietnam. The first analyses an art performance in Yogyakarta Indonesia, where participants from different classes, genders, and educational backgrounds co-create mandalas articulating their imaginaries of organic agriculture. Beans, plantlets, soil and plastics became actants in their own right. The second case studies performative protests by diverse citizens of Hanoi - students, families with children, artists, and members of the LGBTQIA+ community - in response to plans to fell more than 6,000 trees. This challenged the hegemony of science-based discourse by affirming the mutual affective relationships between humans and trees. In both cases, living matter such as trees, plants, seeds, and soil becomes agents in the performative representation of people’s entanglements with their more-than-human environment. We compare the performativity of environmental protest and art along the dimensions of 1) representation, 2) creative expression, and 3) multispecies relations. To conclude, we reflect on how the cosmologies of Southeast Asia inform current multispecies relationships in the context of technoenvironments both in Indonesia and Vietnam.