This is another Arabic dish I learned while living in Syria. This dish is a lot of work but well worth it.To make it correctly, the zuchini must be very small, under 6" long. Hollowing them out perfectly takes years of practice but you can still use zuchinis that you have poked holes through. Try to hollow them out as much as possible so the walls feel thin. You may be able to find a special tool for this purpose at an Arabic store or you can use a thin metal potato peeler with a sharp point on one end. After washing, cut off the stem and insert the tip of the peeler into the middle of the zuchini and turn it, pushing down into the zuchini at the same time. You want to try to remove as much of the white part as possible. Core the zuchinis first, before starting anything else in the recipe. I have seen other recipes saying to use an apple corer to hollow them, but I have never done this myself. The rice should be soaked in hot water for 2 hours before cooking and thoroughly washed so its water is clear, not cloudy. This reduces its cooking time. Do not substitute margarine for the butter. It is mostly water and will evaporate and burn before browning the vermicelli.