Help with door lining in angled door under stairs Kitchens, doors, rails, stud, tables, chairs, stair cases, garden furniture etc... Find answers and ask questions here!

[freewilli]

I have been struggling with how to start and go about building the frame/door lining for a door that needs to have a notch taken out of it to fit under the stairs! the order in which to do things especially

I would appreciate someone who might have done something similar to run me through the steps in order.

Have a fairly good idea of how to do standard doors (non notched) from watching endless videos but would appreciate the input from a chippy on this non standard please and how it would be best to do it!