Asafoetida has a very pungent odour but in cooked dishes it delivers a smooth flavour that is similar to onion. The odour dissipates during the cooking process. It is usually added at the beginning of a Tadka allow it to sizzle in the ghee/oil before adding other ingredients. It is known for its digestive properties, and used a lot in Dals, lentil and pulse based dishes, or other dishes that may build-up gas in the stomach. You will find it show up in many of my recipes too. It is a personal choice to use it, as the the odour puts people off from using it.