I adapted this marvelous recipe from a Lorna Sass cookbook. It's delicious warm, so if you're in a hurry you can serve it right away.
- Peel potatoes and slice 1/4" thick. Cook just until fork tender; drain and transfer to a bowl.
- Add the celery and onion to the potatoes.
- Prepare the dressing: Combine remaining ingredients and stir well or shake in a small jar.
- Pour over the still-warm potatoes and stir gently to combine, making sure all potatoes are coated.
- If desired, add more salt, pepper, or lemon juice to taste.
- Serve warm or at room temperature.