The ornamental design for a cookingdevice, as shown and described.
FIG. 1 is a perspective view of a first embodiment of the new design for a cooking device;
FIG. 2 is a front view or rear view of FIG. 1; the front view and rear view being mirror images;
FIG. 3 is a side view of FIG. 1, the left side view and right side view being mirror images;
FIG. 4 is a top view of FIG. 1;
FIG. 5 is bottom view of FIG. 1; and,
FIG. 6 is a perspective front view of the design in claim 1 shown during use.
The broken line showing of a potato, a pan, and oven rack in FIG. 6 is for the purpose of showing environmental context and forms no part of the claimed design.