Whisk together olive oil, white wine vinegar and Moroccan spice blend in a medium bowl. Place drained white beans in large bowl and mix in enough vinaigrette to coat. Let stand 10 minutes to allow flavors to blend.
Add tomatoes, cucumbers, feta cheese, red onion, and parsley to white beans. Mix in enough vinaigrette to coat. Season bean salad to taste with salt and pepper. Fill pita halves with bean salad and top with dollop of yogurt. Place 2 pita halves on each of 4 plates, pass remaining vinaigrette separately.
*If you can't find Moroccan spice blend at the supermarket, combine 1 teaspoon ground cumin with 1/4 teaspoon each of coriander, cinnamon, and cayenne pepper.
Serve with Romaine salad and bowls of mixed green and black olives.