Bdtyktl

I'm a Canadian, 28/F, working in London, England, here on work visa. I'm in the UK.

The boss is asking me to do something well outside of my job description of virtualization/sysadmin work; she expects me to prepare a meal for eight people to eat (except, the only person eating it is the boss, she said eight people won't be eating it, just her).

I politely told her that I'm not her personal assistant and it isn't in my role of sysadmin, but she insisted "I need to eat at least twelve Victoria sponge cakes, sixteen chocolate bars, thirty packets of crisps, drink nine bottles of Diet Coke, and if you don't get this, I'm demoting you.". She was insistent, said I was such a good worker, nobody else could do the job.

She's insistent about it. BTW, the boss is the owner, if that complicates things, no boss's boss to complain to.

She's also told me that in my role as a sysadmin I have to eat twelve packets of crisps and drink twelve bottles of Diet Coke in a day every single time I'm in the office. I feel concerned, and worry this could damage my health. I work Monday - Friday and occasionally some Saturdays.

I've been in my job for 3 years now, and nothing has ever happened like this before.

How can I negotiate with my boss and tell her politely that I can't do something well outside my job role, given how complex my job is?

What would you advise?