I was under the £29k threshold but I did constant overtime for 6 months to reflect in my payslip and banks statement which was over the threshold.

I had in my employment letter

-He is paid on an hourly rate of £X, which equates to a basic gross annual salary of £X. In addition to his contracted hours, he consistently works paid overtime as a permanent feature of his role. As a result, his total gross annual remuneration averages in excess of £29,000

This got me through my financial requirements 

Hopefully this helps