looking for BA Pretzels
 

I was wondering if any BA cabin crew could help me out. I really like the flavour of the pretzels that are served with the BA meals.
Every time I fly BA i make sure I eat as many packets as possible.
I have searched London supermarkets for an equivalent biscuit but cannot track any down.

The best info I have received so far, is that supermarkets apparently have them available during Christmas only. Is this true? and if not, does anyone know where I could buy an equivalent biscuit?