Welcome to another project by Pete.

YouTube has a lot of videos on chuck boxes, camp Kitchen boxes and galley kitchen boxes for small boats. All excellent and show the great variety of DIY skills.

Rather than buy a ready made ute back camp Kitchen Box I decided to make one. 9mm marine plywood glued and screwed with aluminium extrusions on the corners and a drop down prep area.
Took some time to make and was custom made to fit the specific items.

If you don't have to time or inclination to make your own check out the drifta website. I have had a drifta slide out Kitchen in a camper trailer before. Excellent quality build and large range of sizes from camper trailer model to small table top units.