Knorr do those pots of concentrated chicken stock, I haven't had them but they might do a job. They certainly might if mixed with Marmite, which is what they do to make the Bovril version. If you give me the nutrition info and ingred list for Knorr stock, Marmite and the Bovril Chicken stuff I can probably work up a suitable formulation that will be ambient stable. Certainly fridge stable.
