Filling a door mat void??? Help

I have a receess for a door mat in an entrance porch, Im wanting to fit some laminate/engineered wood floor in that area so obviously need to fill the gap or level it.

Question is whats the best way to approach it?

1. Remove the floorboards in the base of the recess, make a simple frame from 2x1 screwed into joists, relay the boards then ply over the top ready for the laminate?

2. Fill the recess with several layers of ply, then ply the whole area prior to fitting.

3. Another option.

I could really do with some quick replies, Im doing this for my mother in law after work today.

Andy

I filled in a recess for a doormat in our entrance porch about a year or so back, and I just cut some spare timber/veneered wood I had left over from another job I had done to fill it in. I cut it to size, dropped it in, then levelled it using shims. After that I laid hardboard on top of it for a new laminate floor.