Here is how I did it:
Sew the lining and the shell together with 1.5cm seam allowance, make sure that you leave a gap in the middle.
Press the seam open.
Fold the piece in half (right sides together) so that both curved edges meet, press.
Sew 1.5cm seam allowance around the edge. Make sure you don't sew the top edge.
Bag out the pocket through the small gap we left earlier and press.
Secure the opening with a short line of stitching, as close to the edge as possible.
Sew the pocket to the base where ever you would like it and secure down using a double row.
Sew the first line closest to the edge and then the second line inside the first.
I found it helpful to use the foot as a guide.