You can achieve that effect with salt, msg and/or marmite (depending on what sort of flavour you're going for). Inversely, there's things you can achieve with a

You can achieve that effect with salt, msg and/or marmite (depending on what sort of flavour you're going for). Inversely, there's things you can achieve with actual stock that you can't with any of those, mostly related to the texture. If you don't know what's going on, it can be quite dispiriting to read about restaurant-style sauces, learn that one of the key ingredients is stock, and then fail to replicate the effect because the stock you're getting isn't the real deal. These days I just make my own stock (it's dead easy) and freeze it in ice cube trays for easy portioning.