Display screen or portion thereof with a graphical user interface

[0001]The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0002]The FIGURE is a front view of a display screen or portion thereof with a graphical user interface.

[0003]The outer broken lines showing the display screen or portion thereof, and all other broken lines showing portions of the graphical user interface, form no part of the claimed design.