Saucy Portobello Pitas

Ingredients

• CUCUMBER SAUCE:
• 1 cup reduced-fat plain yogurt
• 1/2 cup chopped peeled cucumber
• 1/4 to 1/3 cup minced fresh mint
• 1 tablespoon grated lemon zest
• 1 tablespoon lemon juice
• 1 teaspoon garlic powder
• PITAS:
• 4 large portobello mushrooms, stems removed
• 1/2 teaspoon pepper
• 1/4 teaspoon onion powder
• 1/4 teaspoon garlic powder
• 1/4 teaspoon Greek seasoning
• 2 tablespoons canola oil
• 8 pita pocket halves, warmed
• 8 thin slices red onion, separated into rings
• 8 slices tomato