- 1/4 cup (1/2 stick) unsalted butter
- 1 medium yellow onion, diced small
- 1/4 cup all-purpose flour (spooned and leveled)
- 4 cups low-sodium chicken broth
- 1 pound broccoli, cut into florets, stems peeled and chopped
- 1/4 cup heavy cream
- Coarse salt and ground pepper
- In a medium pot, melt butter over medium. Add onion and cook, stirring occasionally, until softened, 8 minutes.
- Add flour and cook, stirring, until combined, 1 minute.
- Whisking constantly, add broth and 1 cup water and bring to a boil over high. Reduce heat and simmer, whisking occasionally, 10 minutes.
- Add broccoli and bring to a simmer. Cook until broccoli is very tender, 20 minutes.
- Transfer mixture to a large bowl. In batches, fill a blender halfway with mixture and puree until smooth; to allow heat to escape, remove cap from hole in lid, cover lid with a dish towel, and hold down firmly while blending. Return soup to pot as pureed.
- Add cream and heat over medium until warmed through. Season with salt and pepper. Thin with broth or water, if desired.
To store soup, let cool, then cover and refrigerate, up to 1 day.