Gather all ingredients before starting the recipe.
Place whole potatoes in a medium sauce pan, rinse potatoes under running water, then cover with water. Bring to a boil, then reduce heat a fast simmer an cook for 15 minutes, or until the potatoes feel firm tender when pierced with the tip of a sharp knife.
Thinly slice shallots or red onion and add to a medium sized mixing bowl. Add vinegar, oil, salt and black pepper, and stir to combine.
When potatoes are cooked, drain and spread out to cool.
When the potatoes are cool enough to handle, slice in half
Spray a medium skillet with vegetable spray and heat over medium high heat for 2-3 minutes.
Add sliced potatoes, cut side down, and cook until golden brown on the cut side.
Toss potatoes with vinegar and onion/shallot mixture. Adjust seasoning and/or vinegar to you taste.
Serve at room temperature.