Angled Edge Flange gap

I'm trying to build a "pan" and are looking to fill in the corners using the flanges.   The flanges are at a 45 degree angle, however i would like them to get cut enough to fill in the large gaps... Which feature is this? , or is there another way to do this?  I'm using Edge Flange, and angling this at 45 degree.

SolidworksParts And Features