In 5-quart Dutch oven, place potatoes; add just enough water to cover. Heat to boiling. Reduce heat; cover and simmer 10 to 15 minutes or until potatoes are very tender. Drain. Reserve 1 cup potatoes; return remaining potatoes to saucepan. In small bowl, mash reserved potatoes with fork; return to saucepan. Stir in broth, salt and pepper. Heat to boiling. Add broccoli. Return to boiling; cook uncovered 4 minutes, stirring occasionally. Reduce heat to medium. Dissolve flour in milk. Add milk mixture to potato mixture, stirring constantly. Cook over medium heat, stirring frequently, until mixture thickens and boils. Stir in cheese until melted and smooth. Stir in sour cream and onions; cook until thoroughly heated.
|