The ornamental design for a cuttingboard, as shown and described.
FIG. 1 is a top view of a cutting board;
FIG. 2 is a front view of the cutting board, the back view being a mirror image;
FIG. 3 is a bottom view of the cutting board;
FIG. 4 is a right side view of the cutting board;
FIG. 5 is a left view of the cutting board; and,
FIG. 6 is an exploded view of the cutting board with measuring cup insert.
The broken lines of FIG. 3 show an environment of the cutting board and form no part of the design. The broken lines of FIG. 6 show an environment of the cutting board depicting a measuring cup insert that forms no part of the design.