Instructions

1. In a large saucepan, melt the unsalted butter over medium heat until foamy.
2. Add the finely chopped onions and cook, stirring frequently, until they are soft and translucent, about 5-7 minutes. For a sweeter flavor, allow them to caramelize slightly, cooking for an additional 5 minutes.
3. Sprinkle the all-purpose flour over the onions and stir well to combine, cooking for another 2 minutes to eliminate the raw flour taste.
4. Gradually pour in the beef or vegetable broth, stirring constantly to prevent lumps. Bring the mixture to a simmer.
5. Add the Worcestershire sauce, salt, and black pepper, adjusting seasonings to taste.
6. Allow the sauce to simmer for 20 minutes, stirring occasionally to develop flavors and thicken the sauce.
7. Remove from heat and let the sauce cool slightly before pureeing it in a blender or using an immersion blender until smooth.
8. Serve the onion sauce warm over grilled meats, roasted vegetables, or pasta for a delightful flavor boost.