Cook potatoes in boiling water to cover in a Dutch oven 15 minutes or until tender. Drain.
Process potatoes, juice, and next 5 ingredients in a food processor until smooth, stopping to scrape down sides. Transfer mixture to a serving dish, and sprinkle with onions, if desired.
To make your own pita chips, cut 2 (6-inch) pita rounds into wedges; spit in half at seams. Place on a baking sheet coated with vegetable cooking spray; coat wedges with cooking spray. Bake at 450º for 4 to 5 minutes or until crisp.