Culinary query

A couple of times lately, I've seen recipes that call for cooking one ingredient in a steamer basket with all the saucy goodness in the bottom of the pan. What they don't explain is whether the liquid is then supposed to be used as sauce (in which case, why not just cook the steamed ingredient in with it to start with?), or whether it imparts its virtues to the food via the steam (minus the calories, presumably) and then gets thrown away.

Can any of you more experienced cooks enlighten me? I've never put anything other than water-to-be-thrown-out in the bottom of the pan when steaming things.