1. Heat sugar, vinegar and 1/4 teaspoon black pepper, if desired, in saucepan until sugar dissolves.
2. Stir in remaining ingredients except bratwursts and buns. Heat through, if desired.
3. Lift relish from liquid with slotted spoon. Serve warm or chilled over grilled bratwurst with buns. Store any leftover relish, covered, in refrigerator up to 3 days.