Preheat oven to 375 degrees. In a 2-quart or larger baking dish, add rice, butter, and salt.
Stir in boiling water until butter is melted. Cover and bake until rice the water is absorbed and the rice is tender, about 30 to 35 minutes.
Long-grain rice: Any rice works such as long-grain American, basmati, or jasmine. Brown rice takes longer to cook, so plan on at least an hour in the oven.
Butter: It's okay to reduce the butter to 1/4 cup (4 tablespoons). Or, substitute 1/4 cup olive oil.
Yield: This recipe makes about 6 cups cooked rice (1 cup uncooked rice yields about 3 cups cooked).
Storage: Store leftovers covered in the refrigerator for up to 4 days.
Freezer: Spread cooked rice on a rimmed baking sheet to cool (chill it faster in the refrigerator or freezer if you have space). Then, pack into a measuring cup and measure your preferred portion size (1 cup, 2 cups, 4 cups, etc.) into freezer-safe bags. Press flat, label, and freeze. Reheat to 165 degrees.