I normally dress the salad by just pouring some salt, olive oil and red wine vinegar on top of it (in this order). If you get enough practice you will not even need to measure the ingredients. The rule in Spain is that the salad should be oily, salty and not too vinaigry - but I love vinegar (and I also love breaking rules) so my salads (which I eat pretty much every day) are always on the vinaigry side. The alternative to this rudimentary way of dressing salads is to prepare a proper vinaigrette and keep in in the fridge for a few days. You need:
- 200 ml of light olive oil
- 40 ml water
- a tablespoon of mustard (dijon is best)
- a teaspoon of salt
- 2 tablespoons of red wine
Whisk the olive oil and mustard. When the mixture is emulsionated (i.e. it becomes a thick sauce) add the water, then the salt and vinegar. Whisk it a bit more and keep in a jar in the fridge.
You can also do a variation of this by replacing the mustard by a tablespoon of shop-bought mayonnaise and increasing the amount of water to 60 ml.
Whatever you do please do not add any sugar or honey to it - that is the easiest way to ruin any salad.
It keeps in the fridge for a week.