How to Make It
In a medium saucepan, cover the rice with the water. Bring to a simmer, cover and cook over low heat until the rice is tender and the water has been absorbed, about 18 minutes. Remove the saucepan from the heat and let stand, covered, for 5 minutes. Spread the rice on a rimmed baking sheet and let stand until cool, about 15 minutes.
In a large bowl, whisk the olive oil with the lemon juice. Add the rice along with the spinach, scallions, tomato and tarragon; toss well to combine. Season with salt and pepper and serve.