- 2 pounds yellow-fleshed potatoes, such as Yukon Gold, peeled and cut into small cubes
 - Salt
 - 1 1/2 pounds uncooked Italian sausages
 - 2 tablespoons red wine vinegar
 - 1 tablespoon Dijon mustard
 - 1 tablespoon grated onion
 - 1/4 teaspoon pepper
 - 1/3 cup extra-virgin olive oil
 - 1 tablespoon chopped fresh parsley
 
- In a large saucepan, add the potatoes and enough water to cover by 1 inch. Add a pinch of salt and bring to a boil over high heat. Reduce the heat to medium and simmer until softened, about 20 minutes. Drain, transfer to a bowl and cover to keep warm.
 - Meanwhile, prick the sausages all over with a sharp paring knife. Place in a large skillet with enough water to reach a quarter of the way up the sausages. Cook over medium-high heat, turning often, until the water has evaporated, 15 to 20 minutes. Continue cooking, turning with tongs, until the sausages are browned all over, 5 to 7 minutes.
 - In a small bowl, whisk together the vinegar, mustard, onion, 1/2 teaspoon salt and the pepper. Slowly pour in the olive oil, whisking until the sauce is thick and emulsified. Pour over the potatoes and stir gently to coat.
 - Spoon the potato salad onto a platter and sprinkle the parsley on top. Serve the sausages on the potato salad.