1/2 tsp salt
1 1/2 cups long-grain white rice
2 lightly packed cups baby spinach (about half a 5-ounce package), coarsely chopped
1/4 cup toasted slivered almonds or shredded Parmesan cheese, optional
In a 2-quart saucepan, combine the water, lemon half, scallions, and salt. Bring to a boil over medium-high heat. Stir in the rice and return to a boil. Cover the pot tightly with a lid, reduce the heat to low, and cook until the liquid has been absorbed and the rice is tender, about 18 minutes. Remove from the heat.
Quickly sprinkle the chopped spinach over the surface of the rice and re-cover the pot. Let sit until the spinach is wilted, about 3 minutes. Fold the spinach into the rice. Squeeze the lemon juice from the lemon half over the rice, if desired, and discard the lemon. Sprinkle with toasted almonds or Parmesan, if you like, and serve.
If you have any leftovers, store them in an airtight container in the refrigerator for up to 4 days. Reheat in the microwave or a pan on the stovetop, adding a sprinkle of water to the pan and stirring gently until warmed through.