Slightly separate the cabbage from the rest of the food. Now its close to the same colour so it kind of blends into the chop.
The chop does look like its floating and does not look natural. I like the idea of letting the camera see some of the potatoes sticking out. If you do that you might need to suport the other side of the chop with something (edible or safe).
Green does help to break up the browns and blacks. I have found its better to chop the green stuff.
Better lighting would also help.
Here is a pic I took that might give you some ideas.