We claim the ornamental design for a cooking platter, as shown.
FIG. 1 is a top perspective view of a cooking platter showing our new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a front elevational view thereof; and,
FIG. 7 is a rear elevational view thereof.
The figures depicting the bottom, sides and ends of the cooking platter are shown in broken lines and form no part of the claimed ornamental design; these figures are provided for completeness only. Similarly, the top edge of the cooking platter is shown in broken lines and also forms no part of the claimed ornamental design.