I find that doing food photography is done best when the food isnt the only thing in the shot, try setting up a shot with the pizza on a platter with the cheese and pepper shakers on the table. depending on the mood you are going for with the shot maybe even a candle holder and a table cloth. another recommendation i have is don't have such shallow DOF, it should be about the food as a whole, just my opinion.
Agreed. If you're shooting something like apparel, it's fine to knock out the background, as long as you have everything ni focus, then you can take it and put it wherever you want, drop shadows wherever, and make some fake bokeh to make it look half-out of focus.
But food photography doesn't quite work like that.
Try lighting from behind, a large softbox pointed at the camera behind the food. It emphasizes texture, puts highlights on it to make it look more edible, and if there's steam coming off, it emphasizes it. Also, you
must make sure the food you're shooting is fresh. If pizza goes flat when it's not hot, the grease solidifies. People can recognize what old food looks like, even if they haven't eaten it before.
IMO, this needs a more organic setting for it to look nice and less even light.
Something sort of like this, you can see the direction of the light is coming at us, and the image has more context, i'm not a huge fan of the white and green thing in the background though: