The ornamental design for an onionsoupbowl, as shown and described.
FIG. 1 is a perspective view of an onion soup bowl, showing my new design
FIG. 2 is a top perspective view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a right side view thereof; and,
FIG. 6 is a left side view thereof.
The broken lines in the drawings showing the bottom region of the onion soup bowl illustrate environmental matter and forms no part of the claimed design.