Broccoli-Cheddar Soup

5 tablespoons unsalted butter

1 onion, diced

3 cloves garlic, minced

1 teaspoon Dijon mustard

1/4 cup flour

1 quart half-and-half

2 cups chicken or 

vegetable stock

1 head broccoli, cut into very small pieces

1/2 pound sharp cheddar cheese, shredded (not pre-shredded cheese)

Chili oil, for garnish (optional)

In a large saucepan or Dutch oven over medium heat, melt butter. Add onion and sauté until soft, about 4 minutes. Add garlic and mustard and sauté until fragrant, about 30 seconds. Stir in flour. Gradually add half-and-half, stirring constantly. Stir in chicken stock, then add broccoli. 

Bring to a simmer, then simmer until broccoli is tender, about 17 minutes. Transfer half of soup to a blender and blend until broccoli pieces are broken down, then return to pot. Remove pan from heat. Gradually add cheese, stirring constantly. 

Season with salt and pepper and serve with chili oil on the side, if using.