There isn’t much else that evokes childhood summers spent with my French grandmother than a simple salad with a proper, homemade vinaigrette. There’s really no reason to buy dressing for your salads when it’s so easy to make and so lovely to adapt to a particular mood.
The most basic vinaigrette is simply an acidic base (vinegar or lemon juice, typically) and oil. I like mine with a bit more kick so this is the recipe I usually use:
To a splash of red wine vinegar, add a pinch of salt. Then add a dash of mustard (I only ever use Maille!), a clove of crushed garlic, and any additional seasonings you want (chopped herbs for instance).
If using shallots or onions, finely chop and add next.
Finally add the oil and whisk to mix.
Set aside for ten minutes or so.
The important thing here is to always add the oil last. If you don’t, it will coat the other ingredients and the flavors will not blend so well.
Also, never add the vinaigrette to the salad until you are ready to serve. (It’s fine to prepare it at the bottom of the salad bowl then toss it at the last minute.) Otherwise, the acid will cause the leaves to wilt and may make any tomatoes mushy.