1. Cut flowerets off broccoli and divide into small sections.
2. simmer in lightly salted utter 2 to 3 minutes; drain and set aside.
3. Peel stalks and cut into small pieces; cook with onions in 3 Tbsp butter in large saucepan about 5 minutes.
4. Add 3 cup broth and oregano; simmer 20 to 30 minutes or until vegetables are fork tender.
5. Process in blender or food processor until smooth.
6. Melt remaining 2 Tbsp butter in saucepan. Stir in flour and cook until bubbly.
7. Stir in mustard and pepper. Add processed mixture and remaining 4 cup broth; heat to simmering, stirring.
8. Slowly add milk and cheese, stirring constantly.