If you can't find black salt, leave it out. There is no substitute for this unusual, smoky tasting form of rock salt. Though it's called black salt, it actually is more reddish when pulverized. Amchoor, being a dry powdered form of mango, adds the tartness to chaat. It's a handy ingredient for any recipe when you want to add a bit of fruity tartness without additional liquid. Sprinkle a touch of chaat masala on salads, fruit, potatoes, or any vegetable, to perk up the flavors instantly.