In a large sauté pan, cook pistachios over medium heat for 2-3 minutes, giving the pan a good shake or two during cooking. Add the oil to the pan, then add the kale and a couple tablespoons of water to help steam the kale. Cover and cook until the kale is dark green and tender, stirring occasionally. If the kale starts to dry out, add small amounts of water as necessary. Salt to taste.