Cook the rice according to the package directions. Set aside, covered & stirring occasionally to prevent sticking.
In a large skillet, over medium low heat, add the oil. When hot stir in the onions, continue cooking & stirring occasionally until sauteed.
Stir in the curry powder, garlic, and red pepper flakes (if using), and continue cooking for 1 minute.
Stir in the yogurt until evenly combined. Stir in the half & half, or coconut milk, until evenly combined. Bring the mixture to a simmer, and continue cooking for an additional 3-5 minutes-stirring occasionally. Season with salt & pepper, to taste. Stir in the tomatoes & raisins, and remove the skillet from heat.
Divide the rice into six different bowls, or into a single large serving dish, and ladle the chicken curry evenly out over top. Sprinkle the cashews evenly out over top and then with the cilantro leaves, and serve immediately.