1. Bring potatoes to boil in water to cover in large saucepan. Cook 5 to 6 minutes. Add snap peas; cook 1 to 2 minutes longer. Drain well. Cool slightly.
2. Place potatoes, snap peas, olives, onion and celery in large bowl.
3. For the Dressing, mix all ingredients in small bowl with wire whisk until well blended. Add to vegetables; toss gently to coat well. Serve immediately or refrigerate until ready to serve.
To toast fennel seeds: Heat small skillet on medium heat 2 minutes. Add fennel seeds: cook 1 minute or until seeds are fragrant, shaking pan constantly. Immediately remove seeds from skillet to avoid over-toasting.
Test Kitchen Tip: Purple potatoes are small to medium sized and taste similar to russets. They have a dark brownish-violet, thin skin and a bright purple flesh that fades with cooking.