1. Set out a deep saucepan.
2. Remove and discard outer leaves and cut off tough ends of stalks from broccoli.
3. Rinse well. Split heavy stalks lengthwise, about 1/2 in. thick. Cook broccoli in saucepan and drain.
4. Meanwhile, heat butter or margarine in a small skillet.
5. Add onion and cook until onion is tender.
6. Mix in pepper.
7. Pour onion mixture over broccoli. Serve immediately