I always try to incorporate as many of the 5 basic tastes as make sense for the dish, to increase the interplay and complexity while remaining simple. Too much of one aspect and you wind up with a one note dish. Too much period and you wind up with racket.
In my opinion, a perfect recipe does not need a long list of ingredients. You can make a good dish with 3 - 4 ingredients as well, it all depends on the amount of each ingredient you used in a recipe. Which can make it the best or the worst of them all.