Expenses - not showing the currect currency

I have turned on multi-currency.

I have created my vendors/suppliers, and entered in the correct currency in their profiles.

However, the different currencies are not showing up anywhere else.

Most of my expenses are in Sterling/GBP, and are not in my home currency (EUR). 

How do I change this?  This is important for VAT reasons.  

The automated system is picking up the correct figures, yet is showing the incorrect currency. 

I'd appreciate your help.

The only mention of 'multi-currency' in the online tutorials include unhelpful commentaries and tutorials about the theory of foreign exchange arbitrage. 

I don't care: I just want to be able to enter my expenses and have them show up in the correct currency. 

I have bank accounts in the foreign currencies also - and these expenses are paid in the correct currency (sterling) which is not my home currency.