Perfect Brisket BBQ Sauce
  1. In a small saucepan over medium heat, melt the butter. Add the onions and garlic and cook, stirring, until softened but not colored, about 3 minutes. Stir in the ketchup, sugar, lemon juice, Worcestershire, and mustard and bring to a boil. Reduce the heat to low and simmer, uncovered, until thickened, about 15 to 20 minutes.
  2. Use right away, or let cool and store in an airtight container in the refrigerator for up to 2 weeks.