Recipe for disaster (even I think this title is too much)

I'm making a soup right now. I don't have a recipe, and I've never made one before, but I expect it will turn out delicious.

Well, that's not quite true. My roommate, who is a soup genius, gave me some rough directions, which went something like this:

Roommate: "Boil a pot of water and put in dried lentils"
Leora: "How much should I put in?"
Roommate, gesturing vaguely with her hands an amount that could be 1 cup or 1 litre: "This much." I don't know if she meant the lentils or the waer. Or if it matters.

Then I'm supposed to put in whatever vegetables I happen to have in the fridge. And an indeterminate amount of salt. And a bit (is that on the metric scale?) of olive oil. And voila, apparently I'll have made a soup! Seems both easy and incredibly difficult.

Now I'm no Julia Child (I wish I were a spy!), but I cook well enough to not need precise directions. I rarely use a cookbook and enjoy improvising. But this is basically pulling a recipe out of my ass.
Figure 1: half-made ass soup (or for short, half-assed soup)