A jar, some oil, some acid, and thirty seconds of shaking will do more for your cooking than almost anything else.
If there is one habit worth building, it is making your own dressing, because a good one turns a pile of leaves or a bowl of grains into something you actually want to eat. It takes less time than finding the bottle of the store-bought stuff, costs a fraction as much, and tastes incomparably better. All you need is a jar and thirty seconds.
The ratio to remember is roughly three parts oil to one part acid, though the pleasure is in breaking it. Good olive oil, lemon juice or vinegar, a spoon of mustard to hold it together, a little salt, and whatever aromatics you like -- a crushed garlic clove, a pinch of oregano, a spoon of honey. Put it all in a jar, screw the lid on, and shake until it thickens and turns cloudy.
Once you have the base in your hands you can send it anywhere. Sharpen it with more lemon for delicate greens, sweeten it for bitter ones, load it with herbs for a grain bowl, or thin it to spoon over roasted vegetables. Make more than you need and keep it in the fridge; it will last a week and pull a meal together on the nights you have nothing else. This is the smallest possible effort for the largest possible return.
