Hrm, personally I'll prefer to place the subject more towards the top left corner, cos of the red onion, and give some space for the bottom. On top of that, was thinking if you place it that way, the shadows wouldn't be cut off.
However, that's just my personal perception. If you prefer the current composition, you might want to crop of the little shade at the top left corner.
here's another utterly generic but probably applicable ;p suggestion:
-use more space. let the bunch take up about 1/9 of the frame.
-use less space, zoom in until all the cloves are cut off about 1/4 at the sides...