"Healthified" Broccoli Cheddar Soup

Ingredients

• 1 bunch of broccoli, stems and florets chopped and separated
• 1 small onion, finely chopped
• 1 medium red-skinned potato, diced
• 1/4 cup all-purpose flour
• 3 cups low-sodium chicken or vegetable broth
• Kosher salt and freshly ground black pepper
• 1/4 teaspoon freshly grated nutmeg
• 1 cup grated extra-sharp cheddar
• 1 teaspoon Worcestershire sauce
• One 12-ounce can fat-free evaporated milk
• 2 scallions, thinly sliced