This unidentified fern was submitted by Nadhanielle Somonsson who has it in cultivation from plants collected in the Aiyura Valley of the Eastern Highlands at 1500 m. It has since been identified as Goniophlebium subauriculatum by Bernard Sule of LAE herbarium. Thanks Bernard!
Try Goniophlebium subauriculatum
Thanks Bernard! I agree that is a good fit for this species. I will leave the post up for a bit and then edit the name and attribute the identification to you.