I've evolved an unusual cooking philosophy. I use a grr-animals approach of modularity. I think in terms of protein, carbohydrate, and fat (in the correct balance), and try to use only the healthiest, least processed, least glycemic instances of each. This means abandoning ambition of doing the sort of cooking one finds in restaurants, but I've never seen the point of recreating restaurant cooking at home (it's unhealthy, it fails to take advantage of the freedom and flexibility inherent in home cooking, it almost always falls short, and, finally, that's what RESTAURANTS are for!). More on all this here: http://jimleff.blogspot.com/2009/08/h...
That's a standard athletic diet, and while I've gotten healthy and lost weight on it, I've also been bent on making it delicious (something few athletes achieve). I do so via three measures: 1. I further restrict myself to really high-quality, delicious ingredients (i.e. a CERTAIN tofu, a CERTAIN broccolini, etc.), regardless of cost or hassle (I make it back via fewer restaurant bills), 2. I cook with great care and attention, and 3. I have a repository of agents which add je ne sais quoi. Thing is, really really perfect brussels sprouts steamed and served really simply may be delightful once in a while, but, generally, more complexity is needed, and if you're not going to "cheat" with lots of fat and salt, you need ammo for achieving this.
So here's a list of my je ne sais quoi "ammo". All these things can be added in versatile ways to a host of ingredients, and they add that certain something without throwing off the nutritional balance (or dominating the flavor). These are subtle coloring agents.....secret ingredients....ways of developing a signature style to your cooking. Please add on your own suggestions!
Armenian pomegranate molasses
Philippine kalamansi lemon soy sauce
A range of high quality miso pastes (e.g. from South River)
A really good tamari (e.g. South River's miso tamari)
Apple cider (especially cider just beginning to turn)
White wine (especially riesling)
Very high quality spices (e.g. Penzey's ground cumin)
Pumpkin butter (I like Muirhead Pecan Pumpkin Butter http://chowhound.chow.com/topics/580511)
Ginger (my trick is to cut with a potato peeler)
Mexican mole pastes
Anything from the onion family
Black mustard seeds (pop them in a bit of hot oil to launch any pan cooking)
Finely-diced very ripe pear (which dissolves, adding body and flavor)
Hummus (not as an ingredient, but served alongside simple steamed vegetables for dipping)