Cook the black chickpeas: Soak the dry chickpeas for 8 hours or overnight. Drain the soaked black chickpeas and add them to the pressure cooker. Pour in 2 cups of water, just enough to cover the chickpeas, add ½ tsp salt, and seal the lid. Cook on high heat for about 5 minutes or until the first whistle, then turn the heat to low and continue to cook for 15 minutes. Turn off the heat and wait for 5 minutes for the pressure to subside. Using a spoon or a kitchen towel, lift the whistle to release any remaining pressure. Open the pressure cooker, drain the chickpeas, and set aside to cool.

Roast the sweet potatoes: Heat the oven to 375°F (190°C). Wash and thoroughly scrub the sweet potatoes, pat dry, and cut into thick, 6-inch-long batons. Spread the sweet potato sticks on a baking tray, brush with the peanut oil, season with salt, and bake for 10 to 12 minutes or until they can be cut into with a fork. Bring the tray out and allow to cool.

Cut the cucumbers and bell peppers into a large dice.

To make the dressing: In a blender, add the peanut oil, powdered jaggery, red chile powder, tamarind paste, garlic cloves, and rock salt. Blend until thick and creamy.

In a large bowl, arrange the black chickpeas, roasted sweet potato, cucumber, and bell pepper. Pour the dressing over the salad, garnish with sesame seeds, and serve.