SOUTH CAROLINA MUSTARD BARBECUE SAUCE

• 1 tablespoon butter
• 1 slice bacon, cut crosswise into 1/4 inch slivers
• 1 small onion, finely chopped
• 3/4 cup Dijon mustard
• 3/4 cup firmly packed brown sugar
• 3/4 cup distilled white vinegar
• 1 tablespoon hot sauce (preferably Crystal), or more to taste
• Coarse salt and freshly ground black pepper

1. Melt the butter in a heavy nonreactive saucepan over medium heat. Add the bacon and onion and cook until lightly browned, 3 to 4 minutes. Pour off all but 1 tablespoon fat.
2. Stir in the mustard, brown sugar, vinegar, and hot sauce. Let the sauce simmer, uncovered, until thick and richly flavored, 6 to 10 minutes. Taste for seasoning, adding more hot sauce as necessary and seasoning with salt and pepper to taste.
3. Let the sauce cool to room temperature before serving. In the unlikely case you have any mustard sauce left, store it in a clean jar in the refrigerator. It will keep for at least a week; bring it to room temperature before serving

Makes about 3 cups