Combine the quinoa, water or broth, salt, olive oil and currants in a medium sauce pan. Bring to a boil over medium heat. Reduce the heat to low, stir and cover the pot. Cook the quinoa for about 15 minutes or until the liquid is absorbed. Turn off the heat and let the quinoa sit for 5 minutes. Fluff the quinoa with a fork. Stir the pistachios into the quinoa. Spoon the quinoa mixture into the cavity of the squash halves. If you want to serve the dish hot, put the stuffed squash into the oven for 10 minutes to re-heat. Finish with a splash of good balsamic vinegar.