Your grandmother was using a classic French cooking technique called oignon piqué: sticking whole cloves into an onion to flavor a dish.
The cloves slowly release their warm, aromatic flavor while the onion infuses the cooking liquid. It’s commonly used in soups, stocks, sauces, and dishes such as French onion-based preparations. The cloves are also easy to remove afterward because they’re attached to the onion rather than floating loose in the dish.
A practical tip: use 2–4 whole cloves for one onion, depending on how strong you want the flavor. It adds a subtle savory-spiced aroma without requiring ground spices.
So the trick isn’t really a secret health remedy—it’s a simple French culinary technique for flavoring food and making the cloves easy to retrieve.
