Street stalls from Mumbai to Delhi share a surprisingly small pantry, and the same four preparations appear across pani puri, bhel puri, sev puri, dahi puri and vada pav, only in different proportions, because a vendor working from a handful of pots can serve a dozen dishes. Green mint-coriander chutney, sweet tamarind-date chutney, a dry roasted garlic chutney and thinned yogurt are the workhorses, and none is difficult to make. Each, however, carries a specific duty in the finished dish, and knowing that duty makes it much easier to fix a chutney that is too flat, too sweet or too thin, instead of starting over and hoping for a better result.
Green chutney: herbal heat and freshness
Fresh mint and coriander leaves are blended with green chillies, ginger, salt and a souring agent, usually lemon juice or a little raw mango or tamarind, and the result supplies a raw, herbal sharpness that no cooked spice blend can imitate. Most cooks blend it with only a small splash of water into a smooth, pourable paste, because too much water dulls both colour and flavour, and many make it thick and loosen it only when serving. A pinch of sugar rounds off the chilli heat without making the chutney taste sweet. In a sealed container in the refrigerator it keeps for about 3 to 4 days, although the vivid colour fades somewhat by the second day, and a few drops of lemon juice stirred in help it hold its shade a little longer. When it tastes flat the cause is nearly always too little salt or acid and rarely too little spice, so taste it with a grain of salt in mind before adding more chilli.
Tamarind-date chutney: the sweet-sour backbone
This is the chutney that lends bhel puri, sev puri and dahi puri their rounded, nearly jammy sweetness. Tamarind pulp is simmered with dates or jaggery, roasted cumin and often a pinch of dry ginger powder and red chilli powder, and it is reduced to a thick, spoonable syrup. The long simmer is important because it softens the dates completely and lets the tamarind's sourness blend into the sweetness instead of sitting above it as a separate sharp note. The right texture coats the back of a spoon without running off at once, nearer to a thin syrup than to a jam. Thanks to its sugar and acid it keeps for 2 to 3 weeks in the refrigerator, so it is one of the few chaat chutneys worth making in a large batch. A batch that tastes too sour can be simmered with a little more jaggery, while one that turns cloying is brought back by a splash of extra tamarind pulp or a squeeze of lemon.
Dry garlic chutney: pungent crunch
Best known as the filling smeared inside a vada pav bun, this chutney is a coarse, dry powder instead of a wet paste, made by pounding roasted garlic cloves with dried red chillies and salt, often with a spoonful of desiccated coconut or sesame for body, until the mixture crumbles between the fingers and does not cling to them. The garlic is generally dry-roasted or fried very lightly beforehand, which softens its raw bite into something deeper and more savoury while keeping its punch. Since it is dry, it lasts much longer than the wet chutneys, up to a month in an airtight container at room temperature and longer in the refrigerator, and that explains why vada pav sellers keep big batches ready. Its role in a dish is as much about texture as taste, because a spoonful inside a bun or over a chaat adds a gritty, pungent edge that cuts through soft, starchy partners like potato and bread.
Yogurt: cooling creaminess, not an afterthought
Plain whisked yogurt, sometimes lightly sweetened and salted, is the fourth essential, and it is easy to underrate because it resembles a garnish more than a chutney. Its purpose is to cool and smooth everything around it, the tamarind's sourness, the green chutney's heat and the sev's saltiness, much as raita calms a spicy curry. For chaat it is whisked until perfectly smooth and loosened with a little milk or water until it pours instead of mounding, because a thick dollop sits heavily on top of the dish and does not blend into each bite. A pinch of salt and sugar whisked in just before serving makes a clear difference, since unseasoned yogurt tastes flat and faintly sour next to the other chutneys. For chaat, fresh yogurt is best used within a day of whisking, as it keeps souring while it stands.
How the four work as a system
No chaat uses all four at equal strength, and the real skill lies in deciding which two or three lead for a given dish. Pani puri depends almost entirely on green chutney dissolved into the water itself, with tamarind water offered as a milder, sweeter counterpoint for people who want less heat. Bhel puri and sev puri use tamarind as the backbone and green chutney as an accent, because too much green would push the plate toward a herb salad and away from a sweet-savoury snack. In dahi puri yogurt takes the lead and both chutneys are drizzled lightly on top, since the yogurt supplies most of the texture and flavour. Vada pav is the one dish built on the dry garlic chutney, usually with a thin green chutney spread on the bun and little or no tamarind. Thinking of the chutneys as a small system, and not as a fixed recipe, makes adjusting to taste straightforward: more tamarind when a dish seems one-note sour, more green when it seems flat, more yogurt when it seems harsh, and more garlic chutney when it needs a savoury, textural lift.
Storage and make-ahead sense
The four chutneys keep so differently that most home cooks do better to prepare them on separate schedules than to make everything just before serving. Dry garlic chutney and tamarind-date chutney both reward batch cooking, as they last for weeks and change very little. Green chutney is best made a day or two ahead at most, and yogurt should be seasoned close to serving time. Holding all four in small sealed containers in the refrigerator turns chaat into an assembly job instead of a full cooking project each time, which is how most home kitchens and stalls manage to produce a whole chaat spread quickly.