1. Wash the rice thoroughly, changing the water several times. Cut the green scallion stems diagonally into two inch lengths. Chop the white part of the scallions fine.
2. Melt the butter in a large saucepan. Add the minced white scallion and saute until tender. Add the rice, salt and two cups chicken broth. Bring to a boil, stir once and reduce the heat. Cover tightly and cook over low heat until the rice is tender and the liquid is absorbed, about thirty five minutes. If necessary add more broth as the rice cooks.
3. Meanwhile, remove the ends and strings from the peas. Cut the mushrooms and water chestnuts into thin slices.
4. Heat the oil in a large skillet. Add the scallion stems, peas, mushrooms, water chestnuts and almonds and saute only until the mushrooms are tender.
5. Transfer the cooked rice and vegetable mixture to a casserole. Add salt and pepper to taste and sprinkle with toasted almonds. Mix lightly and keep hot for serving in a very slow oven.