Toss asparagus with salt. Arrange in a large (12-inch) skillet with a lid. Add oil and juice to skillet and cover. (The asparagus can be set up a few hours ahead.)
About 10 minutes before serving time, turn burner on high. When asparagus starts to steam, set timer for 4 minutes. Cook until tender, checking at 4 minutes with the tip of a sharp knife.
Transfer cooked asparagus to a serving dish. Add optional zest to skillet and continue to cook until pan juices reduce to a glaze consistency, 2-3 minutes longer. Pour over asparagus and serve.
