What is the French term for a bay leaf stuck onto a section of raw onion with a clove, used to season soups and sauces?

The French term for a bay leaf stuck onto a section of raw onion with a clove is indeed "onion piquet." This technique is traditionally used to infuse flavor into soups and sauces without having to retrieve the bay leaf later, as the onion can be easily removed. The clove not only secures the bay leaf onto the onion but also adds its own unique aroma and flavor, enhancing the overall dish.

The other terms refer to different culinary concepts or seasoning blends. A "bouquet garni" is a bundle of herbs, often tied together or placed in a cheesecloth, used for flavoring stocks and soups. "Poulet" simply means chicken in French, and "herbes de Provence" is a mixture of dried herbs typically associated with southern French cuisine, but it does not refer to the specific method of using onion and bay leaf together.