The aubergine first absorbs all the oil, and then, when you add the mushrooms, it absorbs the liquid released by the mushrooms. So, there's not actually much liquid. But of course, you must not water it.
Because these aubergines are very mild-tasting, you can't taste them; they all have a mushroom flavor.
Another thing: we salt and pepper the mushrooms only at the end to prevent them from releasing more liquid.