- Toast pine nuts (or silvered almonds) in a medium dry skillet over medium-low heat, stirring constantly, until lightly browned and fragrant, 2 to 3 minutes.
- Transfer to a small bowl to cool.
- Add oil to the pan and heat over medium heat.
- Add chopped onion and salt; cook, stirring occasionally, adjusting heat as necessary, until soft and golden brown, 15 to 20 minutes.
- Meanwhile, steam broccoli until just tender, 4 to 6 minutes. Transfer to a large bowl. Add the nuts, onion, vinegar and pepper; toss to coat.
- Serve immediately.