Directions1. In a large saucepan combine potatoes with salted water to cover by 1 inch and simmer until just tender, about 15 minutes.
2. While potatoes are cooking, in a medium heavy skillet cook bacon over moderate heat, stirring, until browned and crisp and transfer with a slotted spoon to paper towels to drain.
3. Drain potatoes and let stand until cool enough to handle. Slice potatoes and in a bowl combine with bacon. Keep mixture warm, covered.
4. Pour off all but 2 Tbsp. fat from skillet and sauté onion over moderately high heat, stirring, until softened, about 3 minutes. Add sugar and 1 Tbsp. vinegar, and simmer 2 minutes. Add onion mixture to warm potatoes with parsley and remaining 1 Tbsp. vinegar, tossing gently, and season with salt and pepper.
5. Serve potato salad warm or at room temperature, garnished with parsley.