Peel potate and cook: Peel potatoes, and place in a large pot with enough water to cover by several inches. Bring to a boil over high heat, add 1 tablespoon salt, and reduce to a gentle boil. Cook until potatoes are tender when pierced with a knife, about 10 minutes.

Heat vinegar, sugar, and remaining salt: While the potatoes cook, combine the vinegar, sugar, and remaining 2 teaspoons salt in a small saucepan, and place over medium heat until the sugar is dissolved.

Drain potatoes: Drain potatoes into a colander.

Cut potatoes into rounds: Using gloves or paper towels to protect your hands, slice the hot potatoes into ⅛-inch-thick rounds and place in a large bowl.

Add hot vinegar mixture to potatoes: Drizzle with hot vinegar mixture, gently stirring until all potatoes are coated. Set aside.

Cook bacon: Saute bacon in a large skillet placed over medium-low heat, stirring frequently, until browned and crispy.

Remove bacon from skillet: Remove with a slotted spoon; transfer to a plate lined with paper towels. Drain excess fat from skillet, leaving a thin coating in bottom.

Saute onions: Add onions to skillet; saute until translucent but not browned.

Add beef broth to skillet: Add beef broth; bring to a boil over high heat. Reduce to a simmer, and cook until reduced by half, about 20 minutes.

Pour over potato salad, add bacon and parsley; serve: Pour over the reserved warm potato mixture, and sprinkle with the reserved bacon and chopped parsley. Gently stir to combine, and serve immediately.