Wash the unshelled shrimp well, leaving droplets of water on them, and put them in frying pan (no oil). Sprinkle with turmeric; then cover tightly and steam over medium heat for a minute or two. Remove cover and stir. The shrimp should have turned pink but not cooked. Rinse in cold water. (The turmeric will make a mess in the sink, so be prepared with scouring powder and sponge.) Shell and devein the shrimp as soon as they are cool enough to handle. Set aside until curry is made. Cover bottom of same frying pan (if some turmeric remains, that's fineÃ¢â‚¬â€don't wash it out) with oil to a depth of about 1/4 inch. Heat; then add onions. Cook and stir until onions are quite brown but not burned. Add ingredients in the order listed down to the cooked rice. Simmer for a few minutes. If mixture becomes sticky, add a small quantity of water. A few minutes before serving, add together the salt and shrimp. Let cook gently about 5 minutes, stirring once or twice to allow shrimp to absorb seasonings. If the 5 minutes are up before you are ready to serve, turn heat off and don't reheat until ready, or shrimp will become rubbery. Serve with hot rice and with chutney or with diced raw zucchini or cucumber mixed into plain yogurt.