Pittsburgh Ham Barbecues

Ingredients (11)

• + ½ cup butter add to pantry
• + 1 small onion, finely chopped add to pantry
• + 2 cups ketchup add to pantry
• + ⅓ cup distilled white vinegar add to pantry
• + ½ cup water add to pantry
• + 3 tablespoons brown sugar add to pantry
• + 2 teaspoons prepared yellow mustard add to pantry
• + 2 tablespoons Worcestershire sauce add to pantry
• + 1 ½ pounds chipped chopped ham add to pantry
• ✓ 8 kaiser rolls, split
• + 1 cup pickle relish add to pantry