How to Make It
In a large saucepan, cover the chickpeas with 4 inches of water. Bring to a boil and simmer over moderate heat, stirring occasionally, until the chickpeas are tender, about 2 hours; drain.
In a large bowl, combine the tomato, cucumber, red onion, jalapeño, olive oil, vegetable oil, lemon juice, cumin, cayenne and mango powder. Add the chickpeas and season with salt. Serve at room temperature or slightly chilled.
Dried mango powder, also known as amchoor, is made from sun-dried green mangoes. It's available at Indian markets and from kalustyans.com.