Combine the Marinade ingredients in a bowl. Add the chicken and toss to coat. Cover and refrigerate for a minimum of 3 hours (max 24 hours).
Once chicken is marinated and ready to cook, prepare the Curry. Start by heating the butter over high heat in a large fry pan. Take the chicken out of the Marinade but do not wipe or shake off the Marinade from the chicken (and do not use or discard the Marinade left in the bowl into the fry pan, set aside for later).
Remove the pieces of chicken (and any Marinade on the chicken cubes) from the Marinade and place chicken in the fry pan. (NOTE: Do not use or discard Marinade in the bowl. Set aside for use in the next step.) Cook chicken for 3 minutes or until chicken is white all over.
Add the tomato sauce, cream, sugar and salt. Also add any remaining Marinade. Turn down to low and simmer for 20 minutes. Add salt to taste.
While the chicken cooks, start the rice. In a medium saucepan, bring the water to a boil. Stir in the rice, butter and salt and return to a boil. Reduce heat to low and cover. Simmer for 15 minutes or until all water is absorbed. Let stand for 5 minutes. Fluff with a fork when ready to serve.
Serve the chicken over the rice and top with cilantro.