Read down the chutney list of the chaat recipes in this library and you will notice the same few names turning up again and again, only in different amounts. A mint-coriander green chutney, a sweet tamarind-date one, a dry roasted garlic powder and some thinned yogurt carry pani puri, bhel puri, sev puri, dahi puri and vada pav alike. None of them is hard to make, and you can usually have all four ready in an afternoon. What matters is that each has a particular job on the plate. When you know that job, a chutney that tastes flat, too sweet or too thin becomes something you can fix on the spot, and you don't have to start over and hope for the best.
Green chutney, for herbal heat and freshness
Make green chutney by blending fresh mint and coriander leaves with green chillies, ginger, salt and a souring agent, usually lemon juice or a little raw mango or tamarind. It supplies the sharp, raw, herbal heat that a cooked spice blend simply can't copy. Blend it with only a small splash of water until it forms a smooth, pourable paste. Too much water dulls both colour and taste, so many cooks blend it thick and thin it only when they're ready to serve. A pinch of sugar rounds off the chilli without making the chutney sweet. In a sealed container in the refrigerator it keeps for roughly 3 to 4 days, although the bright colour fades a little by the second day. Stirring in a few drops of lemon juice helps the green hang on a bit longer. When you taste a batch, do it with a bit of something plain, like a piece of puri or a spoon of boiled potato, since chutneys always seem sharper on their own. If yours tastes flat, the problem is almost always too little salt or acid and rarely too little spice, so think of a grain of salt on your tongue before you reach for more chilli.
Tamarind-date chutney, the sweet-sour backbone
This is the one that gives bhel puri, sev puri and dahi puri their rounded, nearly jammy sweetness. Put tamarind pulp in a pan with dates or jaggery and roasted cumin, plus a pinch of dry ginger powder and red chilli powder if you like, and simmer until it reduces to a thick syrup that you can spoon. Don't rush the simmer. It softens the dates completely and lets the tamarind's sourness blend into the sweetness instead of sitting above it like a sharp edge. Look for a texture that clings to the back of a spoon for a moment before it slides, nearer to a thin syrup than a jam. Remember that it thickens more as it cools, so stop a little earlier than you think. Thanks to its sugar and acid it lasts 2 to 3 weeks in the refrigerator, so it is among the few chaat chutneys worth making in a big batch. If a batch turns out too sour, simmer in a little more jaggery. If it feels cloying, a splash of extra tamarind pulp or a squeeze of lemon pulls it back.
Dry garlic chutney, for pungent crunch
You may know this one as the chutney inside a vada pav bun. It is a dry, coarse powder and not a wet paste. Pound roasted garlic cloves with dried red chillies and salt, and add a spoonful of desiccated coconut or sesame for body if you want it, until you get a mixture that crumbles when pinched and never clumps against your fingertips. If it clings, it still holds moisture and needs more pounding or a minute in a dry pan. Dry-roast the garlic first, or fry it very lightly, so the raw bite mellows into something deeper and more savoury while keeping its punch. Because 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. That's one reason vada pav stalls keep big batches on hand. On the plate its role is as much about texture as taste. A spoonful smeared inside a bun or scattered over a chaat adds a gritty, pungent bite that cuts through softer, starchy things like potato and bread.
Yogurt, more than a garnish
It's easy to overlook plain whisked yogurt because it looks like a topping and not a chutney, yet it is the fourth essential. It cools and smooths everything around it, from the sour tamarind to the heat of the green chutney to the saltiness of the sev, in the same way raita calms a spicy curry. For chaat, whisk it until completely smooth and loosen it with a little milk or water until you can pour it, not spoon it. A heavy spoonful just rests on top of the plate and never reaches every bite. Whisk in a pinch of salt and sugar just before serving, because unseasoned yogurt tastes flat and slightly sour next to the other chutneys. For chaat it works best within a day of whisking, since it keeps getting more sour as it sits.
Putting the four to work together
No chaat uses all four at the same strength. Your skill lies in picking the two or three that lead for the dish in front of you. Pani puri depends almost entirely on green chutney dissolved into the water, with tamarind water as a gentler, sweeter alternative for people who want less heat. Bhel puri and sev puri treat tamarind chutney as the backbone and green chutney as an accent, because too much green would push the dish toward a herb salad and away from a sweet-savoury snack. Dahi puri gives yogurt the lead and uses both chutneys sparingly as drizzles, since yogurt supplies most of the texture and flavour. Vada pav is the one dish built on dry garlic chutney, usually paired with a thin smear of green chutney on the bun and little or no tamarind. Seeing the chutneys as a small system and not a fixed recipe makes adjusting to taste simple. Add tamarind if the dish tastes one-note sour, green if it feels flat, yogurt if it seems harsh, and garlic chutney if it needs a savoury, textured kick.
Storing them and planning ahead
Since the four keep so differently, most home cooks do better making them on separate schedules and not all at once just before serving. Dry garlic chutney and tamarind-date chutney both repay a big batch, as they last for weeks and hardly change. Make the green chutney a day or two ahead at most, and season the yogurt close to serving time. If you keep all four in the refrigerator in small sealed containers, chaat becomes a matter of assembly and not cooking from scratch each time. That is exactly how home kitchens and stalls manage to put a full spread together so quickly.