2 lbs. fresh broccoli
3 tbsp. butter
1/4 c. finely chopped onion
2 tbsp. flour
1 qt. whole milk
1 1/2 c. grated Cheddar or Swiss cheese (I use Velveeta cheese)
1/4 tsp. salt
Sour cream or yogurt, optional

Wash broccoli and clean off leaves and trim stems. Cook in heavy saucepan with just enough water to cover. Cook until tender, about 15 minutes. Drain. Puree in blender or food processor; set aside.

Melt butter in heavy pan and saute onions until tender. Whisk in flour, gradually whisk in milk a cup at a time. Whisk in broccoli. When hot stir in cheese. Stir until melted. Add salt and serve.