Step 1: Prepare the Soup Base : In a large pot, melt butter over medium heat. Add chopped onions and cook until translucent, about 5 minutes. Add minced garlic and sauté for 1 minute until fragrant.
Step 2: Make the Roux : Sprinkle the flour over the onions and garlic. Stir constantly for 1–2 minutes to cook the flour and form a roux.
Step 3: Add Liquids : Gradually whisk in the chicken or vegetable broth, followed by the half-and-half. Continue whisking to avoid lumps. Bring the mixture to a gentle simmer.
Step 4: Cook the Broccoli : Add the broccoli florets to the pot. Cover and simmer for 10–15 minutes, or until the broccoli is tender.
Step 5: Add Cheese and Seasoning : Reduce heat to low. Stir in shredded cheddar cheese until fully melted. Add salt, pepper, nutmeg, and Dijon mustard (if using) to taste. Keep warm on low heat.
Step 6: Prepare the Bread Bowls : Cut a circular lid from each bread loaf and carefully hollow out the center, leaving about 1 inch of bread around the edges to hold the soup.
Step 7: Assemble and Serve : Ladle the hot broccoli cheddar soup into the prepared bread bowls. Garnish with extra shredded cheese, parsley, or croutons. Serve immediately.