Combine the cooked rice, scallions, raisins, and lemon juice in a large bowl and stir. Season with salt to taste.
Toast the walnuts in a dry, heavy skillet (preferably cast iron)over high heat until they turn brown in spots and smell fragrant. Transfer nuts to a dish and set aside to cool.
Quickly wipe the surface of the skillet with a clean towel; melt the ghee in the skillet over medium heat and stir in curry powder; stir for 30 seconds.
Add the cucumber slices. Cook, stirring constantly, until the cucumber is tender, 3-4 minutes. Remove skillet from heat.
Add the cucumbers to the rice mixture and toss to combine. Refrigerate for at least 1 hour.
Toss the toasted walnuts with the salad, then sprinkle a generous amount of paprika over the top. Serve chilled or at room temperature.