- 15 minutes
- 20 minutes
- Bring a pot of salted water to a boil. Add broccoli. Boil for one minute, then add the small pasta shells. Cook as directed on the small pasta shell box.
- Turn off the heat, and reserve one cup of pasta/broccoli water, but discard remaining water through a colander. Return the broccoli and pasta to the dry pot to keep warm. Using a large spoon, thoroughly mix the pasta and broccoli together, breaking the broccoli pieces apart and evenly distributing it throughout the pasta shells.
- In a large pot with a heavy bottom, melt butter over medium low heat. Whisk in flour, and allow the butter to start bubbling. Cook for 2-3 minutes to eliminate the flour taste, whisking occasionally to prevent overcooking.
- Slowly drizzle in the whole milk, whisking continuously to combine. Once the milk is fully added, repeat this step with the chicken broth. Add onion powder, dry mustard, and salt and pepper to taste.
- Bring the pot to a low boil, then turn to a simmer. Allow to simmer 15 minutes. Stir occasionally, and add more salt and pepper to taste (if needed).
- Once the liquids have thickened a bit, turn the heat off. Grate in the white cheddar cheese, stirring as it is added. Allow the cheese to melt completely into the soup, then add the pasta shells and broccoli. Stir to combine. Stir in shredded rotisserie chicken, if using. Serve warm, and enjoy!