Before you cook the prawns boil your rice. The prawns are ready in a few minutes. Clean your prawns and rinse them well. In case of frozen prawns, thaw them and rinse them. Drain the prawns and mix them with the corn starch. Make sure the starch covers the prawns. This will help to keep them tender during cooking. Chop your spring onions with as much of the green stems as possible. Clean the garlic and smash it with a garlic press or cut it into fine pieces.
Now heat the oil in a large pan. Throw in the spring onions and fry them for about 2 minutes until they turn slightly transparent. Then add the garlic and keep on frying for another minute while stirring well. Now it is time to include the prawns. Fry them for another minute, and then toss the wine, the water and the butter over the prawns. Bring to a boil and simmer for another minute or so, until the sauce thickens thanks to the starch. Add salt and pepper according to your taste and serve immediately. If you like your food spicy, you can add 2 fresh green chilies together with the garlic.