There is recipe for what is widely considered as one of the best example of the classic French sauces: the vinaigrette. Its English translation says it all: French dressing. It is believed that it is a French migrant: le chevalier d'Albignac (1739-1825)* that introduced the way of dressing salads with a seasoned mixture of oil and vinegar to the London High society.

The vinaigrette is "the odd one" of the sauce world. In opposition to all emulsion sauces that are made of oil droplets dispersed in a continuous phase of water, the French dressing is the dispersion of water droplets in a continuous phase of oil.

There is not a recipe for the vinaigrette as such. It is just a basic proportion: a 1/4 vinegar or lemon juice to 3/4 of oil seasoned with a bit of salt and white pepper.
In a bowl, pour a tablespoon of good red wine vinegar and dissolve a pinch of table salt into it (salt does not dissolve in oil). Then, stir in 3 tablespoons of vegetable oil. Finally, season with some freshly ground white pepper.
Nowadays, the choice of vinegar and oils that can be used in a French dressing is quite wide. It is traditionally dictated by the type of salad leaves that are to be dressed.

*Chapter VII.
Toute Francaise, a ce que j’imagine,
Salt, bien ou mal faire, un peu de cuisine.
Belle Arsene, Act. III.
In a chapter written for the purpose, the advantages France derived from gourmandise in 1815, were fully explained. This was not less useful to emigres; all those, who had any alimentary resources, received much benefit from it.
When I passed through Boston, I taught a cook, named Julien, who in 1794 was in his glory, how to serve eggs with cheese. Julien was a skilful lad, and had, he said, been employed by the Archbishop of Bourdeaux. This was to the Americans a new dish, and Julien in return, sent me a beautiful deer he had received from Canada, which those I invited to do honour to it, thought admirable.
Captain Collet also, in 1794 and 1795 earned much money by the manufacture of ices and sherbets.
Women always take care to enjoy any pleasures which are new to them. None can form an idea of their surprise. They could not understand how it could remain so cold, when the thermometer was at 26 [degrees] Reaumur.
When I was at Cologne, I found a Breton nobleman, who thought himself very fortunate, as the keeper of a public house; and I might multiply these examples indefinitely. I prefer however to tell of a Frenchman, who became very rich at London, from the skill he displayed in making salad.
He was a Limousin, and if I am not mistaken, was named Aubignac, or Albignac.
Poor as he was, he went, however, one day to dine at one of the first restaurants of London. He could always make a good dinner on a single good dish.
While he was discussing a piece of roast beef, five or six dandies sat at the next table, and one of them advanced and said, “Sir, they say your people excel in the art of making a salad. Will you be kind enough to oblige us?”
After some hesitation d’Albignac consented, and having set seriously to work, did his best.
While he was making his mixture, he replied frankly to questions about his condition, and my friend owned, not without a little blushing, that he received the aid of the English government, a circumstance which doubtless induced one of the young men to slip a ten pound bank bill into his hand.
He gave them his address, and not long after, was much surprised to receive a letter inviting him to come to dress a salad at one of the best houses in Grosvenor square.
D’Albignac began to see that he might draw considerable benefit from it, and did not hesitate to accept the offer. He took with him various preparations which he fancied would make his salad perfect as possible.
He took more pains in this second effort, and succeeded better than he had at first. On this occasion so large a sum was handed to him that he could not with justice to himself refuse to accept it.
The young men he met first, had exaggerated the salad he had prepared for them, and the second entertainment was yet louder in its praise. He became famous as “the fashionable salad–maker,” and those who knew anything of satirical poetry remembered:
Desir do nonne est un feu pui devore,
Desir d’Anglaise est cent fois piri encore.
D’Albignac, like a man of sense, took advantage of the excitement, and soon obtained a carriage, that he might travel more rapidly from one part of the town to the other. He had in a mahogany case all the ingredients he required.
Subsequently he had similar cases prepared and filled, which he used to sell by the hundred.
Ultimately he made a fortune of 80,000 francs, which he took to France when times became more peaceful.
When he had returned to France, he did not hurry to Paris, but with laudable precaution, placed 60,000 francs in the funds, and with the rest purchased a little estate, on which, for aught I know, he now lives happily. His funded money paid him fifty per cent.
These facts were imparted to me by a friend, who had known D ‘Albignac in London, and who had met him after his return.

Extract of The Physiology of taste By Jean-Anthelme Brillat-Savarin

Suitable for vegan, vegetarian, coeliacs, pregnant women, lactose intolerant people and diabetics.