At Vik's Chaat Corner, in Berkeley, California, this zingy chutney offsets the deep-fried richness of the samosas. Seed the chiles if you'd like it less hot, and add the yogurt for a more mellow flavor.
Whirl all ingredients in a blender until very smooth. Drizzle in just enough water to loosen, about 1/4 cup. Season to taste with more chile, lemon, or salt if you like.
Make ahead: Up to 1 day, chilled.
Vik's Chaat Corner, Berkeley, California