Surface from edges

Hi. I’m having trouble creating a clean surface from non planar edges. I’ve tried many ways to solve the issue but can’t arrive by myself to the desired result, which is a surface that would be “properly” place withing the boundary. I did try working a bit through minimal surfaces or kangaroo relaxation, but without luck.

Can anyone help me with this? (164.2 KB)

I downloaded your file but cannot help you since I’m not using Pufferfish and Lunchbox.

I replaced two of your topic tags so other people know about the use of the plugins.