The ornamental design for a roastingstick, as shown and described.
FIG. 1 is a perspective view of a first embodiment of a roasting stick in accordance with the present invention.
FIG. 2 is another perspective view of the roasting stick of FIG. 1.
FIG. 3 is a front view of the roasting stick of FIG. 1. The back view is a mirror image of the left side view. The top view, and the bottom view are the same as the front view.
FIG. 4 is a left end view of the roasting stick of FIG. 1; and,
FIG. 5 is a right end view of the roasting stick of FIG. 1.
Broken lines are used to illustrate features of the roasting stick which form no part of the claimed design.