- 2 tablespoons butter
- 1 cup chopped onions
- 2 cloves garlic, minced (optional)
- 1 head cauliflower, trimmed and cut into 1-inch pieces
- 4 to 5 cups low-sodium vegetable broth
- 1 cup milk
- 4 ounces grated cheddar cheese (about 1 cup)
- Salt and pepper, to taste
Melt butter in a large soup pot over medium heat. Add onions and cook until soft, 6 to 8 minutes. Stir in garlic and cauliflower. Cook, stirring occasionally, until cauliflower just begins to soften, about 10 minutes.
Pour in broth and milk and bring to a boil. Reduce heat to a simmer and cook until cauliflower is very tender, about 30 minutes.
Let soup cool slightly and then carefully puree until smooth (either with an immersion blender or in batches in a blender or food processor). Return soup to the stove over medium-low heat and sprinkle in cheese. Stir until cheese is melted and smooth. Season to taste with salt and pepper.