Melt 3 tablespoons butter in a saucepan over medium heat
Whisk in 3 tablespoons all-purpose flour
Cook for 1 to 2 minutes, stirring constantly
Slowly whisk in 2 cups beef broth
Add 1 cup heavy cream
Stir in 1 tablespoon Worcestershire sauce
Add 1 teaspoon Dijon mustard
Season with salt and black pepper to taste
Simmer until thickened, about 3 to 5 minutes
Serve warm over Swedish meatballs