Trim and floor around top of stairs

[climbinggeorge]

I wasn't sure if this should be posted in decorating, flooring or joinery.

We've got 20mm wundatherm with 18mm engineered wood going on top as a finished floor.
However as you come up the stairs the boarding on the inside of the stairwell stops at the previous sub floor level.

I need to find a way to cover the 38mm showing, and apparently the engineered wood trim can't do it. I'm scratching my head on the best way to do it, I'd prefer not to put a fascia in.
I'm sure I'm not the first person in the world with this issue, any ideas on a good way to solve it?

Attached photos from an earlier stage show the issue with a red arrow / red line

 

 

[Mr Punter]

I have covered the edge with stainless angle on one job:

 

[climbinggeorge]

Thanks for the photo, makes it far easier for a discussion with my partner