Scrub potatoes and place in a large pot. Fill the pot with enough water to cover the potatoes by an inch or so. Bring to a boil over high heat, add 1 tsp salt when water boils.
Boil potatoes until tender: 15-20 minutes,depending on size of the potatoes. Drain potatoes and allow to cool enough to handle.
Peel potatoes using a small paring knife and cut into 1/4-inch slices.
Add potato slices in a large bowl and pour the warm beef broth over the top. Top with the vinegar and green onion. Season with 1/2 teaspoon salt and black pepper, to taste. Use a large spoon and stir gently to coat.
Cover the bowl with plastic wrap and marinate at room temperature for 30 minutes. Stir in the vegetable oil and parsley and prior to serving. Use a slotted spoon to serve to keep liquid in bowl.
If making the night before, you may cover and refrigerate overnight. Take it out 30 minutes before serving to warm to room temperature. Remember to gently stir before serving.