A clamshell carton may be erected from a blank for holding a food product. The blank may include various fold lines and corner features such as gussets or glue tabs that facilitate formation of the blank into the clamshell carton that includes a tray and a lid. The tray may have a bottom panel for supporting a food product. The lid may include a window that allows inspection of the food product held in the carton. The carton may include flanges that project outwardly from the tray and lid. When the carton is closed the flanges may define overlapping pairs that may be sealed together to enclose and seal the food product within the carton.