In this recipe, the rice is cooked in boiling water just like pasta. Toss it very gently, or the rice will become gummy.
Fill a medium saucepan with cold water. Add saffron and 2 tablespoons salt. Bring water to a boil. Stir in rice, and cook until rice is tender, 12 to 14 minutes. Remove from heat, and drain well.
Place rice in serving bowl. Add butter and tomatoes, and toss very gently. Season with salt, pepper, and fresh oregano.