1. Place potato pieces and 1 teaspoon salt in a medium saucepan, and cover with water. Bring to a boil. Reduce heat, and simmer for 20 minutes or until the potatoes are tender but still hold their shape. Drain and rinse with cold water. Drain.
2. Combine remaining 1 teaspoon salt, yogurt, and next 6 ingredients (through garlic) in a large bowl, stirring well with a whisk. Add the potatoes, bell pepper, and remaining ingredients to yogurt mixture, and toss gently to coat.