Certainly some healthy food there. :-) Lighting is a bit harsh. Try using a reflector (white poster board works well) to get fill light and eliminate the glare. The big piece of lettuce in the upper right is overwhelming the image. All JMO of course. :-D Good luck in the challenge.
I like the colors of the tomatoes. The lettuce could be a bit greener. I'd like to see more of the white onions? in the corner. I like the sheen on the cucumbers. All in all I think the arrangement could have been a bit better, while the colors, especially of the tomatoes and cucumbers, are pretty good.
The flash is reflecting off the cucumber a little harshly. Diffusing the light a little more would help this picture. The lettuce does not seem as crisp as it could be