In a large saucepan, melt the butter over moderate heat. When the foam subsides, add the onions, garlic and ginger and fry, stirring occasionally, for 5 to 7 minutes or until the onions are soft and translucent but not brown. Add the red pepper and fry, stirring occasionally, for 3 minutes. Add the rice and fry, stirring constantly, for 3 minutes. Pour in the chopped tomatoes with the can juice, and enough water so that the liquid covers the rice by J-inch. Season with the salt and pepper and bring to the boil. When the liquid is boiling vigorously, cover the pan. Reduce the heat to very low and simmer for 15 to 20 minutes or until the rice is cooked and tender and all the liquid has been absorbed.
Remove the pan from the heat. Spoon the rice on to a warmed serving platter. Sprinkle over the spring onions and serve immediately.