To cook the butternut, warm 2 tablespoons olive oil in a large skillet over medium heat. Once the oil is shimmering, add the cubed butternut and 1 teaspoon salt. Toss to coat. Cover and cook, stirring occasionally, for 5 minutes, then uncover and continue cooking until the butternut is tender and the edges are nice and caramelized, about 7 minutes. Transfer the butternut to a medium-sized serving bowl to cool.