Thick, creamy broccoli cheddar soup made from scratch with sharp cheddar and tender broccoli florets is a vegetarian crowd-pleaser. A family-favorite soup that's warming and satisfying year-round.
Melt the unsalted butter in a large pot over medium heat. Add chopped onion and carrot, and sauté for about 4 minutes until softened but not browned.
Sprinkle the flour over the vegetables and whisk continuously for 2 minutes to create a smooth roux, avoiding any lumps.
Gradually pour in the vegetable broth while whisking to integrate the roux. Add whole milk and bring the mixture to a gentle simmer—do not let it boil.
Add the broccoli florets and cook uncovered for 8–10 minutes until tender. Stir occasionally and adjust the heat to maintain a gentle simmer.
Turn off the heat. Add shredded cheddar cheese in batches, stirring constantly until fully melted and the soup is creamy. Season with kosher salt, black pepper, and nutmeg. For a smoother texture, blend part of the soup with an immersion blender and combine.