If you make this ahead of time, wait to cook the rice until you're ready to serve the dish. Otherwise, prepare the rice first, as it will stay hot while you assemble the curry.
Prepare the Green Curry Paste.
Combine 1/2 cup of the coconut milk and curry paste in a large saucepan over medium heat. Cook 7 minutes, stirring constantly. Add the remaining coconut milk, and bring to a boil. Add the fish sauce, sugar, and salt. Reduce heat to low. Simmer 20 minutes.
Add the shrimp and beans. Simmer 2 to 3 minutes until shrimp is bright pink--don't overcook. (The recipe can be made up to this point, refrigerated, and reheated later.) Stir in the basil, lime leaves, and chilis.
Place the rice in a bowl, cover with cold water, and rub the rice until the water is cloudy. Drain it in a colander beneath cold water until the water runs clear. Place the rice in a large, heavy saucepan with 3 cups of water. Bring to a boil, and cover. Reduce heat to the lowest setting, and simmer for 20 minutes until the water is absorbed. Remove from heat; let stand 10 minutes, covered. Fluff the rice with a fork before serving with the curry.