Bring a saucepan of water to a boil. Cook the potatoes until tender (a fork slides easily in and out). Remove the potatoes with a slotted spoon. Reduce the heat to a simmer and stir in the vinegar.
Heat a nonstick pan over medium low heat. Once hot, add the oil, sausage, onions, potatoes, paprika, and garlic powder. Season with salt and pepper, and saute until golden brown.
Crack the eggs into a bowl to make sure the yolks don't break. Stir the simmering water in a circular motion then gently place the eggs into the water. (You can poach multiple eggs at once, being careful not to overcrowd the pan.) Cook the eggs in the water for 3-5 minutes, until the whites are firm. Remove the eggs with a slotted spoon onto a paper towel to drain excess water. Season with salt and pepper.
Serve the potato hash with eggs, toast, and plum. Garnish with scallions.