Several Indian culinary traditions exclude onion and garlic entirely, and their food does not taste thin. Asafoetida is the ingredient doing the work those aromatics would otherwise do.
The chemistry overlaps with alliums
Asafoetida is a dried resin from a plant in the carrot family, and its pungency comes from sulfur-containing compounds chemically similar to those that give onion and garlic their character.
That similarity is why it registers on the palate in the same region rather than as an unrelated spice. It supplies a savory, slightly meaty depth.
The raw resin smells acrid enough that a small jar scents a cupboard, which is why it is sold in tiny quantities and stored in tightly sealed containers.
Heat transforms it completely
Added to hot fat for a moment, the harsh sulfur notes convert into something rounder and onion-like. Used raw, it stays unpleasant and dominates a dish.
The window is short, since it burns quickly and turns bitter. Cooks add it after the other whole spices and move on within seconds.
Quantity is measured in pinches. It is one of the few Indian spices where a slightly heavy hand ruins the pot rather than merely making it stronger.
Onion-free cooking rebuilds the base differently
Without onion there is no sweet, bulky foundation to build a gravy on, so these kitchens lean on ground nuts, coconut, tomato, yogurt and gram flour for body.
Ginger, when permitted, and green chile carry the aromatic top, while asafoetida supplies the low savory register underneath.
The result is a distinct style rather than a compromised one, which is why regional cuisines built this way have their own repertoire rather than adapted versions of other dishes.
What is sold is mostly not pure resin
Commercial asafoetida is usually cut with wheat flour or rice flour and gum, both to dilute the strength and to make an intractable resin into a usable powder.
Buyers who need to avoid gluten should read the label, since wheat is a common carrier and the ingredient is easy to overlook in a spice this small.
Strength varies accordingly, so a recipe pinch is not a fixed dose. Cooks calibrate against the jar they own rather than against the quantity a recipe names.
It has a second, older reputation
Asafoetida is traditionally added to pulses and legume dishes, where it is credited with easing the digestive discomfort those foods can cause.
That belief is long-standing and widely held, but it is traditional practice rather than settled clinical evidence, and anyone with a persistent digestive problem should consult a clinician.
What is not in doubt is the culinary logic, since a pinch in the tempering of a lentil dish measurably changes how complete it tastes.