Soldato
camping kettle + tea light wins everytime.
combine it with something like https://www.amazon.co.uk/Raclette-Foldable-Non-Stick-Tealight-tealights/dp/B082WDB5XS
you could probably cook a burger on that bro... you can get ones for chocolate too.
why use a flask you can buy the things you need to boil liquid and cook food for the same price and it's more fun
It's literally to take soup to work with. She won't be cooking with a camping kettle at her desk