mess kit; soldier's cooking utensils
Originally military field cooking gear; now also used in camping and outdoor contexts.
My grandfather says he cooked rice in a mess kit during the war.
camping cookware; outdoor cooking utensils
Modern outdoor use; often refers to a compact metal container for boiling rice or water over a campfire.
I tried cooking rice in a mess kit while camping.
Mixed kanji-kana spelling, common in everyday writing.
Compound of 飯 (han, 'rice, meal') and 盒 (gō, 'box, container'). The kanji 盒 is relatively rare and specifically refers to a lidded container.