地三鮮 (dì sān xiān) is perhaps most euphoniously translated as "three fresh things from the earth". 地 is "earth", 三 is "three", and as I mentioned on Wednesday, 鮮 is "fresh". It's a dish from northeast China (東北/Dōngběi), comforting and homely, simply made by deep-frying cubed potatoes, aubergines, and peppers, then simmering them briefly in a savoury sauce.
The ever-reliable Sunflower has a good recipe for 地三鮮 — the only variations I make are that I stirfry the peppers with the garlic and spring onions rather than deep-frying them (i.e. I remove the bulk of the oil after frying the aubergine), and I use a little sweet bean sauce instead of sugar, as suggested by hunger hunger.
Sinoblogic's 地三鮮 recipe is almost identical, but offers the additional time-saving suggestion of frying the vegetables all together; this does require some judgment as to when to add the next type of vegetable though.
Regarding the specific ingredients, some recipes (and some restaurants) use just green pepper, while others use both green and red peppers. Perhaps the trickiest one to cook correctly is the aubergine; fried aubergines tend to soak up a lot of oil. Sunflower suggests that the solution to this is to make sure you fry them long enough that the oil comes back out again, though this does result in very soft aubergine, which not everyone likes. A recipe posted on Chowhound offers the alternative suggestion of salting them before use, though Sunflower stipulates that you shouldn't do this. Up to you!