When I was a child in the 1960s, we had a Co-operative restaurant that served the most incredible home-made broth. A few years ago, I visited a cafe, and their home-made soup tasted almost identical. Seizing my chance, I asked the proprietor what the ingredients were, assuming they had used lamb or beef bones as I have not managed to recreate this myself over many years of cooking.
I was surprised when they said "Just stock cubes". They weren't able (or willing to tell me) what brand they were, so I am assuming here that they are some commercial variety available in the the UK for the past 50 years or so. I know they are definitely not Knorr or any major supermarket own brand, so what could they be? The only way I can describe them is a very savoury, almost smokey taste that has an incredible depth of flavour. I have tried all the classic ways of recreating this flavour with homemade stock, bones etc. but have not come anywhere close. Both soups were a similar colour and consistency to Heinz lentil soup, and the childhood version definitely had bits of beef in it as I remember the very fine, well cooked shreds of meat.
Any ideas what this mystery ingredient (or possibly technique) could be?