A Polish Triangle concessions applicant proposes a food truck covered in plastic vines. Sandwiches, ice cream, coffee and doughnuts will be on the menu as a mobile kitchen prepares to park on the Polish Triangle plaza this summer. Latent Design, the East Village architecture firm that manages city plaza concessions, has been negotiating with Rays Five Star, a mobile-kitchen startup. The Polish Triangle Coalition recommended the vendor for the Division-Ashland-Milwaukee plaza after reviewing applications May 25. Balkan pita-sandwich vendor Cevapcici will contine serving during Tuesdays on the Triangle after-work performances through Labor Day. The Zebek jazz quartet will perform June 7. The summer entertanment schedule features Latino Experimental Theater, the CSYO Steel Band and Adventure Stage Trailblazers.