Bring 4 quarts of water to a boil in a Dutch oven. Meanwhile, toast the rice in a large skillet over medium heat until it smells faintly fragrant and some grains turn opaque, about 5 to 8 minutes—stir frequently to ensure even toasting without burning.

Stir the salt and toasted rice into the boiling water. Cook, stirring occasionally, until the rice is tender but not soft, about 15 minutes.

Drain the rice through a fine-mesh strainer and spread it onto a rimmed baking sheet. Let it cool completely for about 15 minutes, then transfer it to a large bowl.

Heat the oil in a large skillet over high heat until it shimmers. Add the cauliflower, curry powder, and salt. Cook, stirring constantly, until the spices are fragrant and the curry powder adheres to the cauliflower, about 1 minute.

Stir in the currants and water. Reduce the heat to medium-high and cook until the water has evaporated and the cauliflower is tender, about 3 minutes. Transfer the cauliflower mixture to the bowl with the rice.

Add the cashews, mango, chives, salt, and pepper to the bowl and toss to combine. Let the salad sit for 20 minutes to allow the flavors to meld, then serve at room temperature.