Place 1 1/2 cups quinoa in a fine-mesh strainer and rinse well. Place the quinoa, 2 3/4 cups water, and 1/2 teaspoon kosher salt in a medium saucepan and bring to a boil over high heat. Reduce the heat to low, cover, and simmer until the quinoa is tender and all the liquid is absorbed, about 15 minutes. Uncover and fluff with a fork. Transfer the quinoa to a rimmed baking sheet, spread into an even layer, and refrigerate until cooled completely, 10 to 15 minutes.