Toss asparagus with salt. Arrange in a large skillet with a tight lid. Add oil and juice to skillet and cover.
Turn burner on high. When asparagus starts to steam, bring it to medium heat, 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.
